Here at LSOZI, we take off every Wednesday for a look at the old steam/diesel navies of the 1833-1946 time period and will profile a different ship each week. These ships have a life, a tale all their own, which sometimes takes them to the strangest places.- Christopher Eger
Warship Wednesday, May 13, 2020: Sisu via dugout canoe

Photo via the SA-Kuva archives http://sa-kuva.fi/neo#
Here we see the submarine Vesikko of the Finnish Navy surfacing in the Baltic, 1 August 1941, note her 20mm Madsen cannon, twin periscopes, and net cutter. Built as what could best be described as a demo model with help from a shady low-key U-boat concern, she went on to become Helsinki’s last submarine, an honor proudly held for the past seven decades.
Early Finn submarine efforts
Incorporated into the Tsarist Empire in 1809 as the Grand Duchy of Finland after a relatively one-sided war between Russia and Sweden, the region’s ports and inlets proved vital bases for the Imperial Russian Navy’s Baltic Fleet for over a century with the Gulf of Finland essentially a Russian bathtub. As such, many of the Tsar’s small core of professional mariners hailed from the land.
The Tsarist Navy, between 1901 and 1917, fielded around 50 submarines, most in the Baltic, across 10 different classes which included not only domestic production centered in St. Petersburg/Petrograd but also American, German and Italian-made boats as well. Many of these operated from Finnish ports during the Great War with mixed results and six of the seven Russian subs lost during the conflict went down in Baltic waters. Added to this were a bag of nine small British submarines of the C- and E-class which likewise operated from Finnish waters from 1915 onward.
These two facts made it clear that the Finns had a measure of early respect for the submarine, a weapon that had great utility in the cramped Baltic if used properly.
In late 1917, as Imperial Russia was falling apart and the Bolshevik government was actively courting the Germans for a separate peace treaty to exit the Great War, Finland broke away and declared independence. Meanwhile, the Germans made a move to ally themselves with newly-free Helsinki, a flip that led the British to scuttle all nine of their Baltic-deployed boats at the outer roads of the fortress island of Suomenlinna (Sveaborg) off Helsinki on 3 April 1918 and evac their crews overland. Three days later, the Russians still in relative possession of four late-model American/Canadian-built Holland 602-type boats (AG-11, AG-12, AG-15, and AG-16) sent their vessels to the bottom of the harbor in Hango, another Finnish port.
This left newly-independent Finland with no less than 13 wrecked submarines in their coastal regions, two of which, AG-12 and AG-16, were deemed to be the least damaged and were raised in 1919 for possible use by the new country. The two boats lingered onshore for a decade while a variety of submarine experts from Britain, Germany, and the U.S. cycled through to evaluate returning them back into service. In the end, the two boats were too far gone and were sent to the breakers by 1929 in favor of new construction.
Guten morgen, Unterseeboot shoppers!
This led to the curious operation from Finland’s Turku-based A/B Crichton-Vulcan Oy shipyard to produce a series of small coastal submarines–the first warships to be built in independent Finland. The boats were designed by the Dutch front company Ingenieurskantoor voor Scheepsbouw (IvS), which was, in fact, a dummy funded by the German Weimar-era Reichsmarine using design assets from German shipyards AG Vulcan, Krupp-Germaniawerft, and AG Weser to keep Berlin in the sub-making biz while skirting the ban on such activity by the Versailles treaty.
IvS had previously built boats and shared technology to Turkey, Spain, and the Soviet Union before they moved to start making boats in Finland in 1926. Dubbed a “Tarnorganisation” or camouflage organization by German historians, IvS had one of its principal administrators former German Korvettenkapitän Karl Bartenbach, who had been the Kaiser’s submarine training boss during the Great War.
The first three Finnish-built boats, the 500-ton/208-foot Vetehinen (Merman) class subs, were based on the German WWI Type UB III and Type UC III submarines and served as an early prototype for Kreigsmarine’s later Type VII submarines, the most numerous U-boat type of WWII. All three were constructed side-by-side and were operational by 1931, with IvS training their crews. Their names: Vetehinen (builder’s hull CV 702), Vesihiisi (hull CV 703), and Iku-Turso (hull CV 704).
Then came the tiny 115-ton/106-foot submarine minelayer Saukko (Otter), designed to operate on Lake Lagoda– which was shared by the Soviet Union and Finland– built by Hietalahti in Helsinki.
In this period, Bartenbach, still officially furloughed from the German Navy, was serving in the Finnish Navy directly as an advisor.
These early boats had extensive lessons-learned knowledge gleaned by IvS experts who were reserve Reichsmarine officers during trails and shakedown periods.
This brings us to our little Vesikko.
Enter CV 707, err Vesikko.
Originally constructed as IvS hull CV 707, our feature submarine was built slowly between August 1931 and October 1933 in what Jane’s at the time called “private speculation” and “Is actually a German design.” The Finns had first right of refusal on the boat when it came up for sale, open until 1937.

Submarine CV-707 at Crichton-Vulcan shipyard, shortly after sea trial performed by German submarine specialists from IvS, summer 1933. Her unofficial skipper at the time was Werner “Fips” Fürbringer, the Kaiserliche Marine ace who sank 101 ships during the Great War. He was later promoted to the rank of Konteradmiral during World War II.
Some 134-feet long and displacing just 250-tons when surfaced, she only needed a small 16-man crew but carried a trio of 21-inch torpedo tubes with two spare fish stored inside the hull for reloads.

Her trio of torpedo tubes. Finnish caption “Vesikon torpedoa kunnostetaan. Kirkkomaa 1941.07.27” SA-Kuva 29498

While the Germans used her to test their first generation of G-series torpedoes, the Finns would equip their submarines with British T/30 and T/33 type fish.
Capable of floating in 13.5-feet of clear Baltic water, she could submerge in as little as 40 feet. As it wasn’t intended that she would operate outside of the narrow shallow sea, her dive limit of 300 feet wasn’t an issue. Able to make 13 knots on the surface and 7 submerged, her 1,500nm range would enable a war patrol of up to two weeks. Simple, she had an all-welded single hull with no watertight compartments.
A small, somewhat cramped ship, Germans submariners would dub her type as einbaum (dugout canoe).

Submarine Vesikko in Suomenlinna in her Finnish warpaint after 1937, via Submarine Vesikko Museum collections. She started off simply as CV707.
While deadly, her design could also be used in another capacity– training.
CV 707, as a private boat, was at the disposal of IvS submarine crews operating in Finnish waters and, within a year, the updated design was under construction in Germany as the Type IIA coastal submarine, with KMS U-1 officially ordered 2 February 1935 and commissioned four months later.

German submarine U 1 on trials, 1935, the country’s first “official” unterseeboot since 1919. Note the resemblance to CV707, down to the small tower with twin periscopes and serrated net cutter design.
The resemblance to the Finnish boat is striking.
In all, the Germans would construct 50 Type IIs by 1940 and the type would serve a vital training mission for the Kreigsmarine with a half-dozen later broken down and shipped overland to operate against the Soviets in the Black Sea during WWII.
At the same time sub expert, Bartenbach, had been recalled to serve in the newly formed Kriegsmarine in March 1934, after an official 14-year break, and put on the uniform of a Kapitän zur See. Serving in vital submarine development roles, he would retire as a rear admiral in 1938.
With Parliamentary approval, the Finnish Navy purchased the one-off CV707 in January 1936 and dubbed her Vesikko in May, putting her to work as their fifth, and as it would turn out final submarine.

Submarine Vesikko’s entire crew. In Finnish service, she would go to sea with between 16 and 20 men. In German service, the type, filed with trainees, would usually carry 24 to 30
Soon she was involved in a war, the November 1939-March 1940 Winter War with the invading Soviets, during which she patrolled the Gulf of Finland on the lookout for Red warships until iced in by mid-December.
Allowed to be retained after the tense cease-fire with Moscow, Vesikko again became active in what the Finns have called the Continuation War, their limited involvement against the Soviet Union from June 1941 onward. Vesikko sank the 4,100-ton Soviet transport Vyborg on 3 July 1941 with a single torpedo and survived a resulting depth charge attack to boot. It would be her only significant victory.
Restricted from operations during the Baltic winter, she would spend the summers of 1942 and 1943 on patrol and reconnaissance duties but, as the Soviet Navy typically did not venture out of Krondstadt or besieged Leningrad, where they were protected by rings of nets and minefields, Vesikko did not chalk up any more kills. In fact, Vyborg was the only surface ship ever sunk by a Finnish submarine (although in 1942 Vesihiisi sank the Soviet submarine S 7, Iku-Turso sank the Soviet sub Shtsh 320, and Vetehinen accounted for Shtsh 305 though a mixture of torpedos and ramming).
By the summer of 1944, with the war turning against the Finns and their German allies on the Eastern Front, Vesikko was used to shepherd evacuation transports in Karelia as the Red Army surged forward.
In September, as Helsinki worked out a second cease-fire with Stalin in four years, the so-called Moscow Armistice, the Finnish Navy was sidelined and restricted to port, but spared destruction– for awhile at least. In January 1945, the Allied Control Commission ordered Finnish submarines to disarm and Vesikko’s ammunition and torpedoes were landed for what turned out to be the final time.
The 1946-47 Jane’s still listed Finland with five submarines, including our Vesikko.
As part of the multilateral Paris Peace Treaties that were signed in February 1947, Finland had to temporarily hand over control of their port at Porkkala and cede the Barents Sea port of Petsamo (now Pechenga) which had been occupied since 1944 anyway. There were also naval limits, which included eliminating her submarine arm as well as her largest surface ship, the 4,000-ton “lighthouse battleship” Väinämöinen.
While Väinämöinen would be towed to Leningrad and remained in Soviet hands, renamed Vyborg, until her scrapping in 1966, the Finns were allowed to dispose of their submarines themselves, a process, true to their nature of Sisu, they quietly slow-walked.
By 1953, the disarmed Vetehinen, Vesihiiden, Iku-Turso, and Sauko were sold abroad for breaking while Vesikko had been hauled out and stored at Valmet Oy’s shipyard in Helsinki, where she would remain until 1963 as the Finns made overtures to put her back into service.
It was finally decided to retain her as a museum and she was moved to the Suomenlinna fortress and restored to her original 1939 appearance, opening to the public on the anniversary of the Finnish Navy on 9 July 1973 and has since hosted a million visitors.
Here is a great video from the Finnish Defense Forces including wartime footage of Vesikko in service.
Not a bad record for a factory demo model.
Specs:
Displacement: 250 tons surfaced, 300 submerged
Length: 134.5 feet
Beam: 13 feet
Draft: 13.5 feet
Machinery: 2 × MWM Diesel 700 PS (690 shp) surface, 2 × Siemens SSW Electric 360 PS (260 kW) submerged
Speed: 13 surfaced, 8 submerged
Range: 1,500 @ 7kts surfaced, 40nm at 4kts submerged
Crew: 16
Armament:
3 x 21-inch tubes, forward with up to five British T/30 and T/33 torpedos carried
1 x 20mm Madsen wet mount
1 x 7.62mm machine gun
If you liked this column, please consider joining the International Naval Research Organization (INRO), Publishers of Warship International
They are possibly one of the best sources of naval study, images, and fellowship you can find. http://www.warship.org/membership.htm
The International Naval Research Organization is a non-profit corporation dedicated to the encouragement of the study of naval vessels and their histories, principally in the era of iron and steel warships (about 1860 to date). Its purpose is to provide information and a means of contact for those interested in warships.
With more than 50 years of scholarship, Warship International, the written tome of the INRO has published hundreds of articles, most of which are unique in their sweep and subject.
PRINT still has its place. If you LOVE warships you should belong.
I’m a member, so should you be!