HNLMS O 13

O 13 ran into a fishing boat, HD 7, from Den Helder in the Schulpengat on 26 September 1933, sinking HD 7. With sister ship O 15, O 13 attended the Brussels International Exposition in 1935.[3] Later that year O 13, with the Dutch vessels O 12, O 15, Hertog Hendrik, Van Ghent, Kortenaer and Z 5, sailed around the North Sea, stopping at Gothenburg and Oslo. In 1937 O 13 did convoy duty in the Strait of Gibraltar during the Spanish Civil War,[4] along with Hertog Hendrik, Johan Maurits van Nassau, Nautilus, Java and O 15.[5]

During the German attack on the Netherlands in 1940 O 13 patrolled along the Dutch coast and was attacked multiple times by German aircraft. On 10 May 1940, she sailed to England escorted by the minesweeper Jan van Gelder and arrived in Portsmouth the next day. During the evacuation of Dunkirk and Bordeaux O 13 was on patrol in the English Channel. After the Fall of France O 13 was transferred to the 9th Submarine Flotilla based in Dundee, Scotland, together with the other Dutch submarines O 20, O 21, O 23, and O 24. O 13 sailed on her first patrol from Dundee on 12 June 1940 and disappeared. The submarine was presumed lost on 22 June 1940.[6]

Since there are no German records about O 13 having been sunk it is assumed that the submarine ran into a mine, a distinct possibility since O 13 was patrolling in an area known to have been mined,[7] possibly the same minefield where the Polish submarine ORP Orzeł was lost. One other possibility is that O 13 was rammed by the Polish submarine ORP Wilk, which reported running into an unidentified submarine on 20 June at 0.25 am, but that submarine allegedly had a deck gun mounted forward of the conning tower and O-13 did not.[8] Moreover, the newest analysis of the Wilk's damages shows the most probable possibility: that it collided with a German minefield protector buoy, rather than a submarine.[9] Searching of the O13 wreck in the area of the Wilk's reported collision was fruitless.[9]