Events
On This Day - April 7
| 1909 | C 37 (I 67) | Laid Down |
| 1909 | C 38 (I 68) | Laid Down |
| 1915 | E 17 (I 97) | Completed |
| 1915 | G 12 (I 4C) | Laid Down |
| 1916 | E 30 | Four members of the crew of died from an accident in which there were explosions in Nos. 1, 2 & 3 batteries. |
| 1925 | O 9 (Dutch) | Launched |
| 1942 | Turbulent (N 98) | HMS Turbulent sinks the Italian merchant Rosa M. with gunfire south of Cattaro, Yugoslavia. |
| 1943 | Tuna (N 94) | The German submarine U-644 was sunk in the North Sea north-west of Narvik, Norway, by torpedoes from the British submarine HMS Tuna. |
| 1943 | Artful (P 456) | Ordered from Scotts Shipbuilding and Engineering Co Ltd, Greenock |
| 1944 | Ultor (P 53) | HMS Ultor torpedoes and sinks a large sailing vessel off Monemvassia, Greece. |
| 1944 | Unshaken (P 54) | HMS Unshaken torpedoes and sinks the German merchant Asien off Lista, Norway. |
| 1945 | Statesman (P 246) | HMS Statesman sinks a Japanese sailing vessel with gunfire in the Strait of Malacca. |
| 1945 | Tarn (P 336) / Tijjerhai (Dutch) | Completed |
| 1978 | Spartan (S 105) | Launched |
| 1989 | Komosomolets | 42 crew members died when the Soviet Komosomolets submarine sank in the Norwegian Sea following a fire. The submarine, called the "Golden Fish" among the Northern fleet's officers, was the only of the Mike-class, a unique titanium-hulled submarine commissioned in 1984. Komsomolets could go deep, very deep. Able to dive down to 1,000 meter (3,000 feet) under the surface she was impossible to spot from any American satellites or underwater sound-detections systems. |
