During negotiations in Salzburg and Berlin in May and June 1941, respectively, it was agreed that German Navy would have support from Finland. Two groups of German minelayers with assisting and covering forces arrived in Finnish waters before the war. The Finnish minelayers will add their own barrages between the German "Apolda" and "Corbetha". The Finnish submarines will operate east from the mine barrages and their task is to lay mine barrages on Estonian coastal lanes and attack the Soviet battleships, if possibility arises. The Finnish Naval Forces reported to the Germans that three Finnish submarines are planned to lay mines on Tallin lanes before the "x-day" (Barbarossa) and after that two barrages east from Tallinn to the lane to Kronstadt. The Finnish submarines will operate only east from 25oE. The western area will be free for German submarines to operate. [Jok87].
|The submarines and tender Sisu were moved from Turku-Naantali area to east from Hanko 6-7.6. [Jok87]. Iku-Turso was already in dock in Helsinki [Jok87]. 15.6. at 08.00 all cadre personnel of Naval Forces were ordered to their wartime posts [SPK 18708]. Vetehinen and Vesihiisi sailed 16.6. afternoon from Helsinki to Emäsalo off Porvoo, about 50 km east from Helsinki. The anchorage was north from the Emäsalo island. All boats were reported ready to the Naval Forces HQ 17.6. at 09.00 [SPK 18708]. Vesikko, Saukko and Sisu arrived in Emäsalo in the morning 20. June. All three "Vetehinen" class boats and Saukko were moved further east to Pellinki area one day later. All boats had full ammunition, including mines. In the evening 21.6. Vesikko, Saukko and Sisu moved east to Vahterpää off Pyhtää. The commander of Submarine Flotilla was commander Arto Kivikuru. Commander of Vetehinen was lt-cmd. K. Pakkala, Vesihiisi lt-cmd. Kijanen, Iku-Turso lt-cmd. Pekkanen, Vesikko lt-cmd. Aittola and Saukko lt-cmd. Leino.|
The first round of operation "Barbarossa" in the Baltic Sea began with minelaying operations of German ships and Finnish submarines. First mine barrages were laid on the mouth of Gulf of Finland and on the Estonian coastal waterways. The first operations of Finnish submarines were done under great secrecy. "Vetehinen" class submarines laid three small mine barrages in Estonian territorial waters in the morning the "Barbarossa" began and two days later two barrages more. These five barrages were laid before Finnish Government decided that Finland and Soviet Union were at war.
|21-22.6.1941||Vetehinen sailed from Hamnholma at 22.00 off Loviisa, passed Tiiskeri and continued then on surface towards Vaindlo. At 22.30 near Suursaari smoke was seen and at 23.15 they were identifed as two ships at 10 miles distance sailing from north end of Suursaari towards Stenskär. Lt.cmd Pakkala decided to stop, wait and let the ships pass. After a moment they were identified as a small tug with one smokestack and minelayer Amur, based on the peculiar shape of the latter. Both ships had at least their stern navigation lights on. Soon after the ships had disappeared from sight, 2-3 small vessels were seen using approximately the same course. They were possibly submarines. Vetehinen continued half-dived on surface (tower hatch open and using diesel engines), but as the latter vessels came closer the boat dived to 20 meters at midnight. The weather had been all the time clear, wind strength 1 Beaufort and behind was bright horizon. The diving position was 60o02,3'N and 26o18,16'E and course 174o. One hour later the boat ascended to periscope depth and at 02.15 a steamer showing full lights was seen in bearing 330o sailing to east. The island Vaindlo (Stenskär) was passed at 04 hours and course was changed so that Stenskär, N. Uhti and S. Uhti were passed from east. On the east shore of N.Uhti a patrol vessel was seen and it was slightly larger than Finnish VMV boats. Vetehinen laid barrage No. 5 (20 S/36 mines) between 07.38 and 08.26 in Z-pattern south to north on the area between Louna-Uhti and eastern point of Kundalaht. In the Kunda harbour a 1500 to merchantmen was seen. The boat returned using the same route. During the return trip a submarine (possibly Bolsehvik) was seen at 10 hours east from Louna-Uhti. At 12.05 a 500 ton coastal steamer was seen sailing to course 200o. Vetehinen surfaced at 15 hours in about the same place it had dived. The boat had spent 14 hours submerged and travelled at 4 knots. The batteries were not empty and there would have been charge for two hours more. After surfacing two unknown planes were seen flying course 90o. The boat tied along tender Sisu at 20.47.[T16432/1741][Mer68]
The Submarine Flotilla reported to Naval Forces HQ only 26.6. at 21.30 that Vetehinen had returned from its mission to lay barrage No. 5. The Naval Forces HQ has a note on 28.6. that Finnish intelligence reports that enemy has found and destroyed one mine from barrage No. 5 [SPK 18708].
|21-22.6.1941||The departure for Vesihiisi was ordered from Svartbäck at 21.45. The boat used Glosholm secret lane. At 23.00 while the boat was just on the lane to the open sea a radio message was received to cancel the operation and because of interference the radist could not get the sender. The message ordered all units to stop and wait for further orders. At first it was not considered to order Vesihiisi to return. After meeting Iku-Turso that was returning using the parallel Kalkskär lane the commander decided to get into contact with Flotilla. The first base was Äggskär pilot station, but it had no phone and so it was necessary to sail back to Glosholma guard station. After phone contact to Naval Forces HQ it was clear that the message was only for the units going to Ahvenamaa. Vesihiisi sailed again at 02.25 and dived two hours later at the outgoing lane. The boat travelled the whole distance to mine barrage area submerged. At 05.00 one merchantmen and during the minelaying one schooner were seen sailing to north from Estonian coast. The boat laid barrage No. 3 (20 S/36 mines) between 09.05 and 10.25 on the area between Vaindlo and Kalkgrund. While returning the boat threw a false periscope in the middle of Gulf of Finland as western wind prevailed. The boat returned to Vahterpää the evening 22.6 at 19.40. The boat had spent 12 hours submerged.[T16432/1741][Mer68]
Vesihiisi had engine damage and it was repaired in Helsinki 23-24.6. The Submarine Flotilla reported to Naval Forces HQ only 26.6. at 22.10 that Vesihiisi had returned from its mission to lay barrage No. 3 [SPK 18708].
|21-22.6.1941||Iku-Turso sailed at 21.00 from Svartbäck by Söderskär lighthouse. The boat was also confused by the same radio message as Vesihiisi. Iku-Turso sailed again at 02.24 from Glosholm. The boat used Söderskär lane, sailed east from Kallbådagrund and dived at 04.10. The boat laid barrage No. 4 (20 S/36 mines) between 08.15 and 09.06 north from Mohni. Tne mines were laid in a Z-pattern from south to north. The boat returned to Hakasalo anchorage late on the evening 22.6. The boat had been submerged for 9 hours 42 minutes. When sailing to the operational area a Danish merchantmen was seen near Kallbådagrund sailing to east. At 06.30 two airplanes were seen east flying to north. East from Ekholm a two-masted schooner was seen, probably sailing to west.[T16432/1741][Mer68].
The Submarine Flotilla reported to Naval Forces HQ only 26.6. at 20.15 that Iku-Turso had returned from its mission to lay barrage No. 4 [SPK 18708].
|23-24.6.1941||Iku-Turso sailed at 23.30 from Vahterpää using the Långviran lane to open sea. The boat dived at 01.11 8 miles from Pohjoiskorkea in Suursaari. The boat laid barrage No. 10 (20 S/36 mines) 05.42-06.27 off Estonian coast south from Ruuskeri island. The boat surfaced at 10.13, returned using Hamnskär lane and anchored in Svartbäck west from Emäsalo.[T16432/1741][Mer68]
The Submarine Flotilla reported to Naval Forces HQ only 28.6. at 16.43 that Vesihiisi and Iku-Turso have returned from their mission to lay barrages No. 7 and 10 [SPK 18708].
|24.6.1941||Vesihiisi loaded 20 mines 23.6. afternoon from barge Pargas northeast from Emäsalo. The boat used Hamnskär secret lane to open sea, dived NE Hamnskär at 01.17 and sailed at periscope depth no north end of barrage No. 7 area. The barrage No. 7 (18 S/36 mines) was laid in Z-pattern northeast to southwest 05.16-06.10 NE from Ruuskeri island. The mines 18 and 20 did not fell. The reason was that the mine dropping gear of the shaft did not work and it must be repaired by yard. The boat surfaced 10.05 off Hamnskär. Iku-Turso was seen to surface 2 miles aft. Vesihiisi had in the starboard diesel engine leaking exhaust pipe and leaking cooling shell in cylinders 1 and 2 and leaking inner valve. The starboard engine can not be used in open sea because of large steam cloud forms.[T16432/1741][Mer68]
The Submarine Flotilla reported to Naval Forces HQ only 28.6. at 16.43 that Vesihiisi and Iku-Turso have returned from their mission to lay barrages No. 7 and 10 [SPK 18708].
The Finnish Government decided 25.6.1941 that because of Soviet large scale air attacks a state of war exists between Finland and Soviet Union. The submarines Vesikko and Saukko got permission to move east to Kirkonmaa area at 09.05. The Naval Forces HQ allowed to send Saukko for operations 26.6. at 18.30 [SPK 18708]. The large submarines continued mine laying operations while Vesikko and Saukko started patrolling east from Suursaari.
|25-26.6.1941||Vesikko sailed for its first patrol at 21.15 from Ångisö anchor place south from Munapirtti along the coast to east and then from Kirkkonmaansaari to open sea. The boat dived at 01.00 in Matala secret lane. The patrol area was east from Suursaari and southwest from Someri. The boat arrived in patrol area 06.10. The boat heard several times propeller sounds, estimated distance was always over 10 km and no targets were seen. The return trip began at 17.00 and the boat surfaced 21.06. The boat had spent 20 hours submerged when it returned to archipelago [T16432/1741][Mer09].|
|25-26.6.1941||Iku-Turso sailed at 23.30 from Vahterpää using the Långviran lane. The boat laid barrage No. 11 (18 S/36 mines) 08.30-09.12 south from Vaindlo island. Two mines from the starboard foremost shaft did not fell. The reason was that the bottom mine had fell to the barge during loading. The boat returned east from Kallbådagrund lightship using the Kalkskär lane to Svartbäck. The boat spent 15 hours submerged. West from Ruuskeri at 04.25 there was a stern depth rudder malfunction. The rudder jammed 15 down, the boat got 30o down trim and went down to 34 m. When the boat was straightened using pressurized air the boat surfaced. Ruuskeri did not react and the boat dived immediately. Later there was a same kind of malfunction but nothing special happened.[T16432/1741][Mer68]|
|26.6.1941||Vesihiisi sailed at midnight from Vahterpää. The boat laid barrage No. 12 (18 S/30 mines) 09.31-10.29 from south to north SE from Pien-Tytärsaari island. The boat travelled in the open sea 17 hours submerged. The patrol went uneventfully, except both diesel engines need repairs.[T16432/1741][Mer68]|
|26-27.6.1941||Saukko sailed for its first patrol from Kirkonmaa at 21.00. The task was to patrol north from Suursaari and attack enemy shipping. Information was received from Haapasaari coast guard station that the shipping goes south from Someri to south end of Suursaari. No ships were seen except pilot boat anchored in north end of Suursaari. During the patrol the toilet broke down. The propeller axle and toilet leaked and therefore the boat had too much weight in stern. The dirty bilge water could not be pumped out as it would give away the boat. The boat surfaced 15.15 and returned to Kirkonmaa 20.15.[T16432/1741]|
|27-28.6.1941||Vetehinen sailed from Vahterpää 22.30 and dived in Kaunissaari-Ristikaari line at 23.15. The boat had loaded 19 mines. The weather was clear, calm and slight fog from southwest. The boat laid barrage No. 6 (17 S/30 mines) between Länsiviiri and Pien-Tytärsaari 04.47-05.58 north to south in >-pattern. Two mines remained on surface immediately. The starboard mine shaft II did not work so both mines remained. The boat continued southwards. At 12.40 bomb detonations or large shells were heard in salvos of three for half an hour. No other sightings. The boat surfaced at 20.20. At 21.24 crash dive because of two enemy bombers. Surfaced again 21.40 and sighted again two enemy bomber groups that flew away. Tied up alongside Sisu in Vahterpää at 23.40. Total time submerged 21 hours.[T16432/1741][Mer68]|
|28-29.6.1941||Iku-Turso sailed from Kungshamn at 19.00 and used the Äggskär lane to sea. The boat dived at 20.45 and while moving to southeast 22.30 enemy submarine was seen on surface north from Vaindlo. The commander decided to attack. Course was changed to south. One torpedo was fired 10 miles SW Vaindlo at 23.56 but in darkness the target speed was overestimated. The target changed course to south, stern towards Iku-Turso. At the same time the boat became too heavy, periscope went below surface and when it became clear again, the enemy had disappeared. Another submarine was seen on surface at 04.15 north from Vaindlo but this was too far to get into attack position. The boat surfaced at 19.21, returned using Hamnskär lane and tied up in Kungshamn 21.38. While surfacing two SB-planes flew over the boat and in Skvättan narrows 3 three-engined bombers were fired at. [T16432/1741][Kij77]|
|28-29.6.1941||Saukko sailed at 23.00 from Satamasaari (Kirkonmaa). Because or enemy air activity the departure was delayed and the boat had to dive earlier as planned. The boat was to patrol south from Someri, where enemy traffic had been noticed. As no ships were seen the commander Lt. Leino decided to go to look Someri. In Someri harbour two patrol boats were seen inside the pier. The periscope went hazy. The patrol continued to south again, but the periscope went worse. At 11.45 three vessels were seen in southeast, but it was not possible to get into attack position. The boat surfaced at 17.00 and went to Kukkio fort.[T16432/1741]|
|30.6-1.7.1941||The task for Saukko was to torpedo a ship in Suursaari Suurkylä harbour. Saukko sailed at 23.17 from Kukkio fort. The departure was delayed because the periscope was being repaired. While sailing towards Suursaari the periscope went hazy again and the commander decided to go to Someri and shoot one torpedo on its pier. While approaching Someri from west the periscope went even more hazy and commander decided to turn back and dry it. During the second approach a patrol vessel came behind in front of the periscope, but it did not notice Saukko. Because of hazy periscope and poor visibility the attack was abandoned. Saukko returned to Kukkio at 11.00.[T16432/1741]|
|1-3.7.1941||Vesihiisi got order 1.7. at 17.00 while in Riisholma to go to Kukkio and give fuel for Saukko and then sail during the night 1/2.7. to patrol area KOK 1. When sailing into Kukkio harbour the boat ran aground in 4.9 m lane. No heavier damages, possibly some rivets and plates got loose from the keel. Because of fog the boat could sail only 09.00 from Kukkio. The boat dived 09.59 in Matala lane and sailed west from Someri towards south end of Suursaari. At 14.03 three ships were see in Suursaari direction and boat changed course towards them. The ships were identified as two merchantmen in row and a G-class destroyer on their left side. The first merchantmen was old like Finnish v. Döbeln and painted green, the second was black and white large tug or coaster. The first ship was selected as target, but while approaching the Vesihiisi got too close to 300 m and torpedo went under the ship. Vesihiisi turned away and went deep. The destroyer sailed several times over the boat and dropped 3 depth charges about 3 minute intervals. When the last depth charge dropped the boat was in 40 m and commander decided to lay in the bottom. The boat spent 45 minutes in 62 m depth till the enemy vessels were gone. The boat returned using the Matala lane and anchored in Kirkkomaa 3.7. at 00.01. The commander could not get phone contact to the Flotilla for a day.[T16432/1741]
On 3.7. at 08.46 lt.cmd Kijanen (Vesihiisi) reported directly to Naval Forces HQ, because he could not get phone contact to Flotilla: The boat is in Kirkonmaa. Vesihiisi had shot at enemy destroyer but the torpedoes went under the ship. The destroyer depth charge attack did not cause damages to the boat. [SPK 18708].
|2-3.7.1941||Vetehinen got order to sail from Riisholma to patrol area KOK 31 around Stenskär. The boat sailed 15.09 from Våtskär using the Glosholma lane, continued on surface towards Stenskär and dived 19.00 when the lighthouse was 10 miles away. The boat started cruising NW Stenskär. The boat surfaced 23.25 for look-out and fresh air and dived again 23.43. On 3.7. at 10.01 three merchantmen were seen in south going to east south from Stenskär. The boat tried to close distance but submerged speed was not enough and the mine barrages south from Stenskär would limit steering. The commander decided to surface and attack with deck gun. The boat surfaced at 10.22 so that deck was free for the gun crew to work. As soon as the boat had surfaced another 4000 ton merchantmen appeared behind Stenskär at 5-6000 m distance. Fire was opened at this closest vessel that turned around and escaped at 12-14 knots zig-zagging. The crew seemed to panic after 1 or 2 hits were scored in stern. The shelling was halted as distance became too long and the available AA ammunition did not seem to have much effect. The boat dived again at 10.38. The boat planned to move SE stenskär when at 12.40 two small warships were seen to come towards Vetehinen from south dropping depth charges. The boat turned to north, went down to 40 m and retreated north in silent running. About 20 depth charges were dropped. At 13.40 the boat raised to periscope depth and enemy was identified as Fugas-class sweeper by periscope. At 14.34 the depth charge detonationssatrted again and they came closer. The boat settled to bottom at 34 m. The boat raised again and continued to north at 15.08. At 15.50 depth charges were heard far away. The boat surfaced 18.15 10 miles SE Hamnskär and continued on surface to Ängsjö, where it tied alongside Sisu at 20.42.[T16432/1741].
On 2.7. at 16.00 a radio message was sent to Vetehinen that enemy merchant convoy had sailed from grid square 13428 [SPK 18708].
|2-3.7.1941||Saukko sailed from Kukkio at 23.20 to Someri harbour entrance. The captain decided to shoot one 45 cm torpedo at the pier and one patrol boat. The torpedo was fired from 800 m distance at 04.10. The boat raised so much that periscope had to be lowered and the torpedo could not be followed. The boat made a tight turn to right course 290o. At the same time unexpectedly small explosion was heard and the pier and boat were seen undamaged. The boat moved at full speed in 20 m depth away from the harbour. At 04.46 two depth charge detonations were heard and commander decided to stop the engine. At 04.48 two detonations more were heard and as these were stronger also the gyro compass was stopped. At 04.51 and 04.52 very strong detonations were heard. As the engines were stopped the boat descended to 71 m and then it was necessary to ascend by using engine power. At 45 m depth the boat ran aground at 05.19 and depth rudder was jammed to down position. During the depth charge attack the boat did not dare to use its loud air conditioning system and the bad air started to affect the crew. The situation was made worse by exhaust gases the torpedo had blown into the boat. One by one the men became sick. Over half of the crew were unable to work. At 06.35 the boat surfaced and continued on surface to base arriving 08.45. Fresh air and days rest were enough for the crew to recover.[T16432/1741]
In Kijanen's book boatswain of Saukko describes how the commander decided to surface to get fresh air but was forced to dive again because patrol boat depth charge attack. The boat surfaced after few hours with only five men of 13 remaining conscious, and the sea was empty [Kij77]. The same story is also in Ekman's book [Ekm86] but the book of Pukkila follows the battle report and does not mention the attempt to surface [Puk61].
|The first successful torpedo attack was done by Vesikko on 3.7.1941. Vesikko sailed from Kirkkomaansaari at 19.00 to operational area KOK 1/2. The boat dived in Matala sea lane at 20.47, sailed in periscope depth west from Someri island and arrived to area southwest from Lavansaari. The bright summer night passed without incidents. The return trip started 07.30. At 10.18 a patrol boat was seen in southwest and 12.24 several smokes in southeast. At 12.50 Lt.cmd. Aittola, saw through periscope a large grey merchant vessel bearing 261o, distance 15 000 m. Attack was started. The shooting position was good: target distance 700 m, speed 12 knots, shooting angle 75o. At 13.25 the commander fired a torpedo from number three tube. It hit the target in stern, and the target stopped and started to list to starboard. The boat shot another torpedo from number one tube at 13.34, but it veered to right and passed behind the target. Submarine hunter came from behind and Vesikko dived down to 45 m. Some rustle was heard from deck that was possibly caused by electric trawl to locate the submarine. Thereafter 14 depth charges were dropped in 15 minutes. The nearest detonated about 200 m away causing gyrocompass to stop. Listening device reported that the target sunk 14.15 and submarine hunters ceased their search 15.25. [T16432/1741]
The target was 3900-ton merchant ship Vyborg. This was also to be the largest ship sunk by Finnish submarines. The submarine hunters tried to tow torpedoed ship but the ship went down. The commander offered a small toast to whole crew to celebrate first successful torpedo attack of Finnish submarines. Soon after the midnight Vesikko was back in Vahterpää base and tied alongside tender Sisu 00.17.
The submarine operations were halted 4.7. The Naval Forces HQ sent message to the Submarine Flotilla 4.7. at 09.45 that submarines are not allowed to go to sea before new orders have been given. 5.7. at 09.30 Submarine Flotilla got order to prepare for minelaying operations nortwest and northeast from Suursaari but at 10.00 Commander of Naval Forces ordered that no submarine mine laying operations will be done until further notice and submarine operations in general will be limited to minimum [SPK 18708]. The situation on the sea front was not clear and the bright summer nights were not suitable for submarine operations. 6.7. evening Iku-Turso asked permission to go to Helsinki for engine repair and the boat arrived Helsinki 7.7. at 07.00. Submarine Flotilla reported the boat ready 10.7. at 19.00. The boat sailed the same evening to lay mine barrage No 13.
|10-11.7.1941||Iku-Turso sailed from Kungshamn at 20.37 using Äggskär lane. The boat laid mines off Estonian coast north from Lobi peninsula 02.49-03.28, barrage No. 13 (18 S/36 mines) in >-pattern south to north. Two mines from port side middle shaft did not fell. Because of poor visibility it was not possible to determine location until when laying mine No. 2. The position of the end of barrage could not be verified. Iku-Turso continued patrolling north from the barrage it laid and returned to Kungshamn 18.16. Enemy was not sighted or heard, poor visibility due to haze. [T16432/1741]
The position is given grid squares 14439 and 14436[SPK 18708].
14.7. at 10.10 Submarine Flotilla got permission to send boats to Helsinki for necessary repairs one boat at a time. At 16.25 Iku-Turso was sent to repair cracked exhaust pipe. Vetehinen moved to Helsinki 15.7. at 16.50 [SPK 18708]. 17 July the Naval Forces HQ rearranged securing and sweeping activities in the Gulf of Finland. As the main Soviet naval forces had moved to eastern Gulf of Finland the main tasks were to secure blocking of the mouth of Gulf of Finland and arrange safe transfer between Tallinn and Helsinki as soon as possible. The boats were divided into two groups. Vesikko, Saukko and Sisu were to stay in their current position in Kirkonmaa fort off Kotka and operate east from Suursaari [SPK 18708]. Vetehinen, Vesihiisi and Iku-Turso were planned to move to Helsinki. Their task would be reconnaissance and securing in grid squares 13830, 13860, 14310, 14330, 11820 and 11850. 18.7. at 07.00 Vesikko arrived in Helsinki for engine repair. 19.7. at 02.00 Vesihiisi sailed from Vahterpää to Helsinki for mounting radio antenna and 14.00 Saukko was sent to repair depth rudder and engine hood. Vesikko moved to Vahterpää. In the evening 23.7. enemy planes strafed Sisu and Vesikko in Vahterpää and three men were wounded. Following night Vahterpää was bombed five times, but the ships were already in Kirkkomaansaari. Saukko was repaired 25.7. and 26.7 afternoon it moved to Kirkonmaa. The 2nd group (Vesikko, Saukko and Sisu) was ordered to Helsinki 8.8 [SPK 18708].
Large boats operated against Soviet supply routes to Hanko and Paldiski. The boats were stationed first in Helsinki and then in Barösund, east from Hanko. The submarines began their operations again in the beginning of August. The large boats had their operational area between Pakri island and the Finnish "Kuolemajärvi" mine barrage. Because of confined waters only one of the large boats was sent on patrol at time. The first patrol from Barösund was minelaying operation of Vesihiisi 2.8.1941. Thereafter the large boats patrolled every night.
|1-2.8.1941||Vesihiisi sailed from Barösund at 21.00, continued on surface to middle of Gulf of Finland and dived 01.15. Patrol boats were seen 06.50 2000 m away and they continued to south from Osmussaari. Commander decided to lay the mines on the route the patrol boats had used. Vesihiisi laid barrage No. 17 (18 S/36 mines) east from Osmussaari 07.26-08.15 in Z-pattern south to north. The boat laid 18 mines and 17 of them were heard to settle in determined depth. As the mines had been in shafts for a month the depth settling happened faster as usually. Mine No. 2 settled in 50 seconds, only 60 m behind the boat. The position of the barrage could not be determined from land sightings because of poor visibility. The position was determined using depth sounder and Estonian navigational chart No 18. The boat surfaced 17.17. [T16432/1741]|
|2-3.8.1941||Vetehinen sailed from Barösund 21.00 and passed Gråharu 23.26. The boat dived 01.47. At 06.04 a ship was seen in south and 06.15 it was seen to belong in a convoy that had a Fugas-class sweeper, Щ- and M-class submarines and two patrol boats on the left side (north side). The ships were coming from the sound between Osmussaari and mainland and sailing course 50o. Vetehinen shot one torpedo at the Щ-class submarine, distance 1200-1500 m, target angle 110o, target sped 10 knots. The shooting conditions were not good, but commander decided still to try. The torpedo missed, but enemy did not seem to have noticed the attack. The boat saw several times Fugas-class sweepers but they were too small targets for torpdoes. The boat turned to north 15.17 and surfaced 19.37 8 miles NE Jussarö. The boat arrived in Barösund base 21.53. [T16432/1741]|
|4-5.8.1941||Vesihiisi sailed 23.00 from Barösund to patrol off Paldiski. The boat travelled surfaced across the Gulf of Finland and dived 02.31 close to Estonian shore. At 12.01 the first officer sighted three vessels in bearing 60o sailing course 300o. At the same time a reddish buoy was seen ahead 500 m away and it was possibly a mine as it had horns. The vessels were identified as two sweepers and a 3000 ton merchantmen behind them. Later also two patrol boats were seen. The attack began 12.08, attack angle 90o, distance 10000 m. Both bow torpedoes were fired 12.53, shooting angle 90o, distance 1000 m and depth setting 2 m and 3 m. No detonations were heard. After shooting torpedoes the boat evaded using varying courses, first at 30 m and then at 50 m using half speed and full speed. The patrol boats dropped 15-20 depth charges. Some light bulbs in diesel department and depth meters in tower broke. The detonations were close causing boat to heel. The boat settled to bottom at 70 m for 13.03-13.37. At 14.21 the boat raised to periscope depth and saw smokes of the departing vessels in west. During the time boat was settled in bottom several valves leaked so much that there was a ton of water in bilges. These must be repaired before next mission. The boat surfaced 20.30 east from Jussarö and went to Helsinki for repairs and resupply. [T16432/1741]
The boat drifted inside the "Kuolemajärvi" minefield and after returning to east attacked later a Soviet convoy: transports Hilda and No. 24, sweeper Menzhinskii, patrol boats MO-212 and MO-142. The sea was clear and calm so the attack was risky. Both torpedoes missed the target and resulting depth charge attack was evaded by diving to 78 metres. The boat was docked for two weeks due to leaking bottom valves when it had returned to base. War correspondent Allan Törnudd was with this patrol and his story was published two weeks later, naturally without any names. [Kij77]
|7-8.8.1941||Vetehinen sailed from Barösund at 22.57 and passed Gråharu light 23.57 sailing south. Mast lights of a vessel was seen at 01.05 in east. The boat dived 02.11. A small warship was seen 04.05 NE Pakri going east. 06.50 three Fugas-sweepers were seen going to west. 07.05 two Fugas, two patrol boats and a submarine were seen going west. No possibility for attack. The boat saw merchant vessels and smokes four times 10.12-13.36. The last two ships were seen in bearing 330o and they were attacked. The target was a 1500 ton three-islander that was escorted by two sweepers and couple of patrol boats. Two bow torpedoes were fired 14.55, distance 50 m, estimated target speed 9 knots and shooting angle 90o. Both torpedoes missed as no detonations were hears. After shooting the boat turned left to 330o at 8 knots, dived to 40 m and continued at 4 knots. 15.01 first depth charge detonation, Speed was increased to 6 knots and boat went down to 60 m. 15.03 last depth charge detonation. Seven depth charges were dropped and they detonated 300-500 m away. Depth charge attack did not cause damages. Surfaced 19.12 6 miles SE from Jussarö and arrived in Barösund 21.30, where tied up alongside Iku-Turso. [T16432/1741]
The convoy included transport Hilda and ex-Estonian gunboat Laine. [Kij77]
|18.8.1941||Vesikko sailed from Helsinki 02.00 and dived in Kuivasaari lane 03.30. The boat patrolled in Helsingin matala - Keri area. A convoy was seen 07.40 in bearing 205o, distance 8000 m. At 07.50 it was seen to have 4 small and 2 large merchantmen and 2 Fugas sweepers. The attack was abandoned at 08.05 because the targets were too far, distance 4000 m, attack angle 90o. The boat started return voyage at 15.00 and surfaced 19.45 near Öster Tokan [T16432/1741].|
25.8. Saukko was sailing out when it collided with German Schnellboot S 28 at Harmaja off Helsinki and was in danger to capsize. The submarine was tied to S 28 and saved. Saukko had to be docked.
The Vetehinen made 6 patrols on Pakri area, Vesihiisi 5, Iku-Turso 5, and Vesikko one. The last boat on patrol against Hanko convoys was Vetehinen 26.8. During the Tallinn evacuation no Finnish submarines were out, because the operation "Häämatka" to move gunboats from east to west was going on. The small boats stationed in Kirkkomaansaari did not make any patrols in the eastern Gulf of Finland even though it was planned. During the patrols in Pakri area the submarines shot seven Italian T/40 and two British T/33 torpedoes. The firing positions had been so good that torpedoes should had hit, but they did not. It was later found out that the T/40 type torpedoes had faulty steering system, depth control and detonator. [Kij77]
The Finnish boats ceased patrols at the end of August and were stationed in Helsinki. Tallinn was evacuated 28-30.8. and it was assumed that the Soviet forces in Hanko area would stay there over the winter. 31.8. the Naval Forces HQ informed German command that Finnish submarines will not operate until further notice so every submarine in the Gulf of Finland can be assumed to be enemy and attacked. The Finnish command informed also that in future the boats may be used east from Suursaari and temporarily between the mine barrages, in areas off Helsinki and Osmussaari. The Finnish submarines started training off Helsinki in Katajaluoto and Kuivasaari waters. The maintenance and docking for winter began already in October. Vesikko and Iku-Turso were docked first for painting. When Iku-Turso was ready Vesihiisi was docked for battery maintenance. Of the Finnish submarines Vetehinen, Iku-Turso and Saukko were operational when Soviet Union surprisingly began to evacuate Hanko area. They were sent to operate between Helsinki and Keri lighthouse. Saukko operated during daytime 2.12 and 3.12. From 30.11 to 4.12. during nights, about from 17.00 to 08.00 hours, Vetehinen operated in south and Iku-Turso in north. [Kij77]
|2.-3.12.1941||Iku-Turso sailed from Helsinki 16.30. At 23.15 the Mäkiluoto coastal fort opened fire. 00.03 three flashes were seen in bearing 220o and at 00.54 smokes of two ships in bearing 207o. The ships opened fire and commander of Iku-Turso concluded that Vetehinen is attacking. Iku-Turso had received two messages telling that the first convoy includes a passenger ship and the second one a very large ship, and the commander decided to wait for the second convoy as the first one was too far. At 01.05 Mäkiluoto opened fire again. At 02.28 the second group came in sight directly in south. Iku-Turso tried to get ahead of them sailing course 150o. At 02.45 the ships were seen to be 4 small ships and a destroyer behind them. The distance was 4000 m and target angle 150o so attack was no longer possible. The boat slowed down and turned to course 325o. At 02.31 a heavy explosion was seen in bearing 230o and at 02.49 in bearing 120o. The ships of the first convoy were around the second explosion. Nothing more happened and the boat returned to Helsinki 08.00 [T16432/1741].|
|2.-3.12.1941||Vetehinen sailed from Helsinki 16.45. Mäkiluoto coastal fort was seen to open fire 23.13 and 00.06 explosion was seen in bearing 240o. In the same bearing Mäkiluoto splashes were seen. At 00.21 enemy ships were seen in bearing 230o and 00.40 they were identified as a large destroyer, two Fugas or submarines, two merchantment, the first one possibly a tall passenger ship and 2 patrol boats. 01.08 Vetehinen began torpedo attack on surface at full speed. Moonlight changed so that the boat had bright moon behind and the convoy was in darkness. 01.12 the escorts opened fire and the closest hits of enemy artillery were only 20 metres away. Vetehinen opened artillery fire against the destroyer but it was ceased after 2 shots as muzzle flashes blinded the crew. Bow torpedos were fired 01.15-01.16 and stern torpedoes 01.17-01.19 against the largest vessel. At least three torpedoes were seen to run straight but no explosions were heard. The distance was 2500 m. Two more shots with Bofors were fired, but fire was ceased as no shell splashes could be seen in darkness. The enemy ceased artillery fire 01.25. At 01.38 6-7 vessels were seen in bearing 250 o. As the torpedo tubes were empty and artillery fire was useless, the commander decided to dive. The boat surfaced 02.17 and saw 3-4 ships in bearing 100o, closest one was Fugas sweeper 5000 m away and 2 more ships in bearing 220o. The boat dived again. When submerged several explosions were heard. The boat surfaced 03.07. No ships were seen and boat returned in Helsinki 05.37. Two battle torpedoes were loaded 17.00.|
|3.12.1941||Saukko sailed from Helsinki 07.00 to the operation area of Iku-Turso that had not yet returned. The boats met in Kustaanmiekka sound and Iku-Turso told about the heavy waves. The commander of Saukko decided to go out even though weather was heavy and steering of the boat was difficult because of waves. Assumed German convoy from Tallinn to Helsinki was seen 10.35, 11.35 Kuivasaari battery off Helsinki opened fire and 12.25 while in Kustaanmiekka coming back, Saukko was ordered to attack enemy shipping. The boat returned to Helsinki because the weather was too much for the litte boat [T16432/1741].|
All naval activities ceased after the Hanko evacuation. On the night 3/4 December Vetehinen and Iku-Turso were still patrolling, but it was too late. Enemy had sailed away and Hanko was again in Finnish hands. The Finnish submarines had made 11 patrols against the las Hanko evacuation convoys and only Vetehinen had managed to make one attack. The Baltic Red Fleet was pushed in the very end of Gulf of Finland with very insecure future. The results of Finnish submarines included one merchant ship sunk by torpedo and a few sunk and damaged ships by mines.
It was estimated by Finns and Germans that Soviet submarine arm had still at least 40 boats left. They would most certainly start some operations during the season. Light naval units would also be active. Germany had suggested moving of "Vetehinen" class boats to Polar Sea. Finns considered this unrealistic as the boats had only two weeks operating time. Besides, the Baltic Red Fleet was not finished yet and Finland would need all units it had. During winter the towers of "Vetehinen" class boats had been modified and 20 mm Madsen gun moved from deck to tower.
After the winter Vetehinen and Iku-Turso were ready for operations 16 May. The other boats had overhauls and tests finished in June: Saukko 9.6., Vesikko 10.6. and Vesihiisi 29.6. Overhaul of Vesihiisi was longer as the boats batteries were replaced. As the Italian T/40 torpedoes had been unreliable during the previous year, the boats took in British T/33 torpedoes. Louhi was ordered as tender for the Submarine Flotilla. The new commander of the Flotilla was commander K. Pakkala.
The most successful operation of the Finnish submarines was against Soviet submarines in Ahvenanmeri in 1942. The Soviet submarine offensive had mixed up the sea transport system and all possible units were concentrated to eliminate enemy submarines. The idea to use submarines against their Soviet counterparts was found in June.
At first Vesikko was sent to operate in sea area between Helsinki and Tallinn. This gave no results. In August-September all "Vetehinen" class boats and Vesikko were stationed in Maarianhamina for a very unusual task. The boats were to act as convoy escorts and hunt down their Soviet counterparts. The first proposed tactic was to detect the submerged enemy with hydrophones and then attack with depth charges. During the practices in 11-20 August it was concluded that the best possible method would be totally different. Instead of searching submerged enemy boats, the idea was that by using electric motors and hydrophones it would be possible to surprise enemy submarines on surface loading their batteries. These operations started in September. The Finnish boats would rest by day and hunt by night.
The "Vetehinen" class boats and Vesikko were all equipped with a 12 microphone hydrophone. They were tested first surfaced, but it was found out that waves in 4 Beaufort will lower their performance significantly. It was concluded that when surfaced they were not able to detected submerged enemy submarines, but they could easily detect approaching torpedoes and warn the convoy. When submerged the Finnish boats could detect in cold water merchantman engines from 40-50 nautical miles. The "Vetehinen" class boats and Vesikko were even equipped with four depth charges in a rack on stern. The Finnish boats had their bows painted yellow, in tower was a yellow line and during nights they had a blue-white light showing up. The first depth charge test was done in Vesihiisi 3. August. The boat moved at 10 knots and the depth charge exploded at 45 m depth.
The boats had been operating Ahvenanmeri for almost two months before they succeeded. They had all some contacts but did not got into shooting position. The fuel pump of Vesikko had broken, and after repairs in Helsinki the boat made four patrols there. The large "Vetehinen" class boats remained in Maarianhamina.
|21.10.1942||Vesihiisi sank Soviet S 7 at Lågskär by torpedo. Vesihiisi was patrolling in the south part of Ahvenanmeri, about 12 miles SW from Lågskär (59o50´N - 19o50´E). Vesihiisi sailed at course 220o and located the Soviet boat at 8 000 meters distance in south in bearing 190o. The enemy boat was sailing course 320o at 12 knots. The sky was partly clouded, wind was light and sea was calm. The time was 19.26 so it would have been dark, but the moonlight. The enemy boat was first spotted by my grandfather, who was awarded by his commander, lieutenant-commander Olavi Aittola with a packet of cigarettes. The situation was good for the Finnish boat as the northern horizon was dark and southern light due to moonlight. Vesihiisi changed course to 200o and sailed with full 8 knots speed that electric motors gave directly towards the enemy boat. A few minutes later Vesihiisi changed course to 255o. At 19.41 when estimated distance was 2 000 meters one bow torpedo was fired. The commander believed to have missed as no explosion was seen after two minutes and ordered to open fire with 76 mm deck gun. A detonation was seen in the stern of the enemy boat after only one shot. The distance had been close to 3 000 meters. Four men, including commander Sergei Lisin, were taken prisoner. One of the survivors, starshina V. Kunitsa, had no duties at that moment and had therefore asked permission to enter bridge for a smoke just before the torpedo hit. The wreck of S 7 was discovered in July 1998 by a Swedish diving team.|
|26.-27.10.1942||Finnish merchant ship Betty H. was sunk from convoy by submarine torpedo 26 October. Submarines Vetehinen and Iku-Turso were ordered to hunt. They got a hydrophone contact about 10 miles west from Lågskär and followed enemy boat from 13.27 clock for more than four hours, but then lost the contact. This boat was most likely the Щ 307 that escaped. Vetehinen decided to return to Maarianhamina by the Nyhamn way. Iku-Turso also turned home but decided to make a detour to west and sail into the archipelago through Kobbaklintarna way. It was dark and visibility poor due to drizzle. At 19.40 Iku-Turso turned east to enter the seaway, when suddenly a large enemy submarine was seen closing fast only 100 m away. The enemy boat passed Iku-Turso at 30 m distance and Iku-Turso opened fire with 20 mm Madsen gun. About 50 shots were fired. Some hits were seen in enemy tower, but it disappeared into darkness and drizzle. Iku-Turso got again hydrophone contact and followed it easily. Rain had gone and in moonlight visibility was 4-5 miles. At 23.51 a submarine tower was seen in direction given by hydrophone. The enemy boat surfaced and sailed to east with high speed. At 23.58 Iku-Turso shot two torpedoes against the enemy submarine, believed to be Щ 320. One torpedo was seen to explode behind the tower and 10 seconds after the explosion nothing was seen. The boat sank 00.01 at 20 miles west from Marhällan. On the following morning a large oil slick was seen, with oil coming to surface as a thick tower. Echo sounder showed depth of 150 m. The distance had again been estimated too short (this time it was actually 4 200 meters instead the estimated 2 000 meters) and five gunshots were fired before one torpedo hit. Luck was on the Finnish commanders side. Iku-Turso was commanded by lieutenant-commander Eero Pakkala. [Kij77]|
|5.11.1942||Vetehinen sank Soviet Щ 305 at Gisslan by ramming. One of the convoys had located a submarine in Ahvenanmeri and Vetehinen and Iku-Turso were sent after it. The weather was partly clouded, east wind was light and sea was light. The visibility was poor to southeast - southwest. Vetehinen was in the north part of its patrol area, when at 21.18 it located at bearing 360o a surfaced enemy boat sailing westward. The position was between Gisslan and Simpnäs (60o01´N - 19o11´E). The course was changed towards the enemy that dived after ten minutes. Vetehinen changed its course to 270o. With hydrophone contact was again gained and at 22.50 the enemy boat surfaced less than 1 000 m away. The enemy was now southwest from Vetehinen and sailing approximate course 110o. Vetehinen had to turn towards the enemy to get into a position to shoot the torpedoes. The distance decreased rapidly, speed was lowered and both bow torpedoes shot. The distance was smaller than estimated, only 250 meters, and torpedoes missed probably under the target. Gun fire was opened and with six knots speed Vetehinen charged on the enemy boat. The first 76 mm shell hit enemy tower and commander, lieutenant-commander Antti Leino decided to ram. Vetehinen hit the Щ-class boat ahead of the tower and its net cutter cut deeply in enemy pressure hull. Tense seconds followed; will Vetehinen get loose from its victim, or will they sink together. The Finnish boat had some damages, but returned home safely and was docked a week later. The damages included cracked bow, lower net cutter was gone, starboard depth rudder was jammed and bent 10o down, bottom plates bent for first 10-15 meters, side plating bent for 2 m2 area and number six dive tank was leaking.[Kij77]|
Vetehinen was repaired by Crichton Vulcan in Turku. The boat returned to Maarianhamina 22 November with T/12 torpedoes. The next two days all boats used for torpedo maintenance. The rest of the season was expected to be quiet. In the beginning of December all boats were ordered back to Helsinki. The boats left their depth charges and some torpedoes in Turku. On 9. December boats were lying in fog off Hanko, when they were ordered back to Maarianhamina. Swedes had detected unknown submarines. The large boats were in Maarianhamina 18 December and made few patrols. Nothing was seen and the boats were back in Helsinki 31 December and docked. Before the boats were in Maarianhamina at least Vetehinen (9.12) and Iku-Turso (10.12) had ran aground and needed repairs.
The sailing season of 1943 was quiet for the Submarine Flotilla. The boats had been in Suomenlinna for the winter: Vetehinen, Iku-Turso and Saukko docked in the inner basin and Vesihiisi and Vesikko in Tykistölahti. After the mild winter it was planned to get the boats ready as soon as possible and therefore personnel training was left for the open water season. Iku-Turso was ready for operations 12 April and Vesikko 15 April. The maintenance and repairs of other boats were delayed by material problems. For example Vetehinen was late because the replacement of batteries took much longer than expected. They were still finished in May: Vesihiisi 7.5., Saukko 17.5. and Vetehinen 29.5.
The operational plan of Navy Commander dated 15.4.1943 stated that submarines will be used only, if the enemy gets into the central Gulf of Finland or west from there. The submarines would be used against important surface targets in limited areas off Helsinki, south-east from Jussarö and in the mouth of Gulf of Finland. The submarines would also be used in submarine search south-east from Jussarö, in Ahvenanmeri and, when necessary, also in Gulf of Bothnia. [SPK 23432]
It was seen in early June that Soviet submarines would have a hard time when trying to reach the Baltic basin. In May two Щ-class boats had been sunk, one damaged beyond repair and the fourth had to return after unsuccessful attempts to break the net. It was concluded in June that it was not necessary to keep all boats in operation. The Finnish boats were stationed west from the "Seeigel" mine barrage. No enemy ships managed to sail this far and the submarines used the season for training and other activities. Some of the boats were stationed in Suomenlinna and would practice with Finnish and German submarine hunters, while others would practice with tender Sisu in Turku area and Gulf of Bothnia.
The submarine Flotilla had got new submarine commanders and men during the winter and they needed to practice. Sisu, Iku-Turso and Vesikko trained 16.5-3.6. in Turku area and in the Gulf of Bothnia off Rauma. They returned to Helsinki in the beginning of June. In the beginning of June all boats except Saukko practised with 20 mm Madsens off Helsinki. 12-30.6. Vetehinen, Vesihiisi and Saukko trained in Gulf of Bothnia while Iku-Turso and Vesikko remained in Helsinki. During the training periods in Gulf of Bothnia each boat made about 15 practice attacks.
In the beginning of July Iku-Turso was a target boat for German hydrophone training. 9 July the boat sailed to Tallinn to act as a target for German submarine search practices. Iku-Turso returned to Helsinki 19.7. Vesihiisi was in Tallinn for the same reason 31.7-9.8. 7 August Iku-Turso served as a target in tests to locate submarines on bottom with echo sounders. From July to September the boats served as practice targets for Finnish and German sonar training off Helsinki about twenty times.
New commanders for Vesihiisi, Vesikko and Saukko and some first officers were commanded 16 August and so even more practice sailing was necessary. Vetehinen, Vesikko and Saukko sailed 25.8. to training areas off Turku and in the Gulf of Bothnia. The boats made more than ten torpedo attacks each and returned to Helsinki 7.9. The sea cadet training ship Aura II was also taking part in the training and some of the cadets had a possibility to follow a submarine torpedo attack both as an attacker and as a target.
As no enemy activity had been seen west from Porkkala submarine net, another training voyage was planned. The last training in the west started 13 September when Vesihiisi, Iku-Turso and tender Sisu sailed from Helsinki. A magnetic mine damaged Sisu in Rysäkari near Helsinki. No leaks but ships machinery had heavy damages. The ship was towed back to Helsinki. The old training ship Suomen Joutsen had now to act as tender. The two submarines and Suomen Joutsen sailed to Lappohja 20.9. 14 October Vesihiisi and Iku-Turso sailed to Ahvenanmeri with escorts Aura and Suursaari that served as practice targets. During these exercises Iku-Turso had a dangerous situation [SPK 23418].
|19.10.1943||The Iku-Turso dived at 11.52. Due to the leaking bottom valve of the trim tank there was too much water. Later it was measured to have been 6.5 tons. When the boat was going down the crew could not hold it and the boat went to 54 m. The crew tried to go forward with full speed but only the use of pressurized air helped. The boat was then about 30o stern down and later slightly less bow down. The boat surfaced at 11.59 and then the excess weight was noticed. Because of the heel the tanks could not been blown dry as the blowers using diesel exhaust had leaked. Also some battery acid had spilled over. At 13.30 the damages were repaired and the boat was able to continue with practice attacks.|
As usual, a lot of repairs were necessary during the sailing season. The boats were getting old and problems with materials and spare parts were becoming more severe. The engine of Saukko was removed for repairs at Crichton-Vulcan in January 1944. Vetehinen and Vesihiisi finished their season 30 November. The small boats finished their season 10.1.1944, and Iku-Turso 25.1.1944.
Finnish submarines did a short tour around the Koivisto islands and Bay of Vyborg. Iku-Turso patrolled 19-20.6. southwest from Koivusaari. There were no suitable targets for torpedoes as the large units of the Red Navy remained in Leningrad. MO-boats were too small, agile and numerous as torpedo targets. The "Vetehinen" class boats patrolled in the north end of Koivisto sound after evacuation of Koivisto islands and mine laying operations began again. In the first week of July submarines operated at the Bay of Vyborg area. They were of no use to attack small landing crafts that sailed around Pulliniemi, i.e. from Koivisto islands to Bay of Vyborg. Small units with air cover should have been used. Vesihiisi laid two minefields, 4.7. east from Peninsaari and 8.7 on the mouth of Lavansaari harbour. Vetehinen laid mines on 5.7. to the north end of Koivisto Sound.
|3-5.7.1944||For the Peninsaari mine operation Vesihiisi took full load of 20 mines from barge Pargas 21. The boat sailed 3.7. from Våtskär anchorage. After passing Ulko-Tammio island in the night 3/4.7. the boat sighted two patrol boats and dived to 10 meters. The boat passed Narvi island at 05.00 and sighted Peninsaari on starboard at 09.30. When trying to fix position for mine laying at 10.50 the periscope revealed two "Fugas" class sweepers in bearing 250o. In the calm sea a even fast periscope check could reveal the boat and Vesihiisi was detected by motor mine sweepers. Depth charge attacks were made by MO patrol boats, but these were evaded by diving into 25 m and moving silently at 2 knots straight towards the enemy ships. The enemy had thrown about 20 depth charges, which detonated usually behind Vesihiisi. By hydrophone it was detected that patrol boats had also arrived. At 12.50 minesweepers left the area and sailed to Peninsaari. Vesihiisi continued to lay its mines from 13.05 to 13.47. At 15.00 the patrol boats were seen in bearing 90o. Vesihiisi returned northward submerged and at 18.00 Narvi island was passed. The boat surfaced after being submerged for 20 hours and tied aside tender at 02.30 on 5 July. On 8.7. MO-408 and patrol boat No.172 in Vesihiisi barrage area (2 miles to N from Lavansaari) destroyed by guns 4 drifting mines and 2 mines which were seen in small depth.|
The last Finnish boat to operate around the Bay of Vyborg was Vetehinen on 5.7. Thereafter submarine operations were conducted by German VII C boats. Finnish boats operated west from the Huovari-Narvi-Seiskari line. The boats patrolled one at time, first every day and later every second day as no suitable targets were located. Some merchantmen in Lavansaari harbour rouse interest and Iku-Turso tried to attack them on 23.8. The boat approached in very shallow water, only 1-2 meters under keel. When Iku-Turso turned to shoot stern torpedoes, a small explosive charge detonated in submarine net and the boat suffered some damages, for example both periscopes were out of operation. One periscope was full of water and the other could not be raised. The boat managed to return home without any further incidents. On the following day, during loading of batteries, it was noticed that 20 of them were cracked and acid had seeped to the bilge. Rigorous spooling did not remove all acid. Nine years later, when the boats were made ready for delivery to be scrapped, the aft battery room of Iku-Turso was noticed to have two holes corroded through the pressure hull.
The last Finnish submarine on war patrol was Vetehinen that sailed on 31.8.1944 to Lavansaari but was ordered to keep distance from the harbour. Stormy sea prevented operations. The boat had to dive down to 20 m for wave movement to cease. When the boat rose to periscope its stern rose above surface due to waves. Attack to Lavansaari was abandoned and the boat returned to its base on 2.9. The Armistice began 4.9.1944 at 07.00 hours and Submarine Flotilla remained thereafter in Emäsalo. After the Germans had tried to capture Suursaari on 15.9. the Finnish command was afraid of a similar attack to Ahvenanmaa. Submarines were sent to Nauvo area in full alert. The Peace Treaty of 19.9. forbade Finnish warships to leave harbours as long as fighting continues. Submarines were transferred to Turku on 27.10.1944. On 15.12. Vesikko and Saukko were sent to winter dock in Suomenlinna and in January 1945 the large boats were also towed from Turku to Suomenlinna. Thereafter the boats remained there for eight years. The Finnish boats had sunk one merchantmen and three submarines. Some ships were lost to mines they had laid. Not a single one of Finnish boats was lost.