M-94 submarine

Dive 1/5 on the Hiidenmaa-2020 trip.
We had arrived to our accommodation at Randmae Puhketalo already previous evening. We took the 13:30 Tallink Star from Helsinki Länsisatama harbor to Tallinn, arriving at 15:30, then drove as fast as we could the Rohkula, where we just barely made it to the 17:30 ferry. Did some quick shopping at Kärdla Selver. Arrived to Randmae about 19:30 and then unpacked. Later we had a briefing from Sander.
The travel group was divided into two teams. Our team contained me, Leppis, Eero, Ulla, Keni, Juha, Jankkuri, Kyrö, Hepsu. Our team was to wake up and leave a bit later and use the slower wooden boat from Kalana harbor. We would dive two wrecks, the M-94 submarine and then a newly discovered unknown wreck, that were both 20-30 min boat ride from Kalana. We would have soup lunch at the harbor, and not go back to our place of accommodation. Kalana is at the western tip of Hiidenmaa on the Ristna neem.

I had D12 tanks with Nitrox topped over old Trimix, and my camera set: Olympus TG-6 in PT-058, AOI UWL-4 lens. BGNing tray, attached on each side a Nanight 4000 lumen video light attached to tray with two pieces of BGNing 8" carbon fiber float arms. Main light Nanight T2. 6 kg of weights.

So we left Randmae at 9:30. We had loaded all diving gear to a trailer. A van was towing the trailer, then we had one SUV and Jankkuri’s trasporter. Then at Kalana we loaded all diving gear to the wooden boat. Sander and his friend from Estonian Navy. We left in a sunny nice weather, almost too warm to wear a drysuit.

We arrived to the site of M-94 about 11:30, and then Sander threw in a shot line. Then he dived to the wreck and tied the line to the wreck, so we could moor the boat. Me and Leppis went down first to the wreck, which was lying at 16 to 17 m deep flat sandy bottom. On top of the wreck it was 14 m. Water was quite warm 17 C at bottom. Visibility 5 to 10 m, but above 15 m really poor. Plenty of light at the bottom, you could manage without torch. We did two full rounds, as it was quite small, less than 40 meters long. Then a third round far away from the boat to see the silhouette. Dive time was agreed to 50 min, and that was plenty to see every detail. You could see the periscope prism. On the bottom there was the hatch. Bow of the boat is blown out by a torpedo. After we had all dived, we returned to harbor for lunch and to wait for next dive. The dive operation went without nay issues for everyone on the boat.

Notes about M-94:
M-94 was a Soviet Union Navy submarine of the M or Malyutka class, Type XII. M-94 was launched 11 Sep 1939 and sank by German U-140 submarine on 21 Jul 1941 at a reported position 58° 51'N, 22° 02'E. The wreck was only very recently found by the Estonian Navy at 58°51'51.948"N 22°04'46.783"E.

https://uboat.net/allies/merchants/ship/1036.html
History: M-94 (Yard #118) was laid down in December 1938 at the Zavod No 112 (Krasnoje Sormovo), Gorkij at the River Wolga in sections, which were transported by railway to Leningrad and completed in December 1939.
Notes on event: At 06.55 hours on 21 July 1941, M-94 (SrLt Nikolay V. D’yakov) was hit by one torpedo from U-140 and sank, while the U-boat attacked a second submarine at 07.06 hours with another torpedo, but missed. The second submarine was M-98 which rescued the commander and two survivors with a rubber dingy shortly afterwards. They had been on the conning tower when the torpedo hit and thought that the men inside were dead, but the submarine sank in shallow waters lying on its stern at an angle of 60°. This made it possible for eight men to leave through the main hatch and were brought ashore by a launch.

Malyutka class submarine has a length of 37,50 m and complement 18 men. 2 torpedo tubes.
These boats were designed in the beginning of the 30’s as typical coastal submarines. That is why their abilities were modest enough - initial range of VI-series was just 800 nm (later series had 3400), maximum patrol duration - 10 days and just two torpedoes. But far patrols were not for them - these cheap, mass-produced boats were intended to defend naval bases, blockade enemy harbours and, as a main feature, be railway-friendly to be transported from one war theatre to another. Many of these boats were transported 18.000-20.000 km ashore (by railway) to cover 3000-5000 nm during their sea patrols or even execute patrols on Ladoga Lake near Leningrad. It is reported that Malutkas were world’s first fully-welded submarines as of 1932.
There were four main series of M (Malutka): VI, VI-bis, XII and XV, where each latter has any improvements vs previous series (XV had four bow torpedo tubes) and fought at all theatres - Arctic, Baltic, Black Sea, Caspian Sea and at Pacific. The unusual features and advantages of these boats were confirmed during WWII. Russian word “Malutka” means “baby, little one'”
Only 4 series XV submarines were completed during the war, 11 more were laid down during the war but were completed post war.