The Sen Taka Sho (submarine, high speed, small) was designed to defend the coasts of the Japanese home islands. In bursts of speed, the HA-201 class could run almost 14 knots submerged. The HA-201 class was largely fabricated by welding. Some units of the HA-201 class were fitted with snorkels. They carried four 533-mm (21-inch) torpedoes and were fitted with two tubes. 22 boats were laid down, but only 10 were completed before the end of the war. None made operational patrols.
| Units | 22 |
|---|---|
| Ships | HA-201-HA-238 and HA-246. |
| Year Completed | 1945 |
| Displacement | 320 tons/493 tons |
| Dimensions | 173.4 ft x 13 ft x 11.4 ft |
| Machinery | 1 diesel: 400 hp
1 electric motor: 1,250 hp |
| Speed | 11.8 knots / 13.9 knots |
| Range | 3,000 nm @ 10 knots |
| Armament | 2x533mm TT fwd + 1x7.7mm mg (4 torpedoes). |
| Max. Depth | 100 m (330 feet) |
| Crew | 22-26 officers and men |
