| Submarines of 900 tons (U.25-U.30 completed, and U.31-U.37 completing), range 4,000 miles, speed 18/10 knots, armament 4 torpedo tubes and 4 q.-f. guns: (in commission and completing) | 13 |
| Submarines of 800 tons (U.21-U.24), range 3,000 miles, speed 14/9 knots, armament 4 torpedo tubes and 3 q.-f. guns: (in commission) | 4 |
| Submarines of 400–500 tons (U.19-U.20), range 2,000 miles, speed 13 ½/8 knots, armament 3 torpedo tubes and 2 q.-f. guns: (in commission) | 2 |
| Submarines of 300 tons (U.9-U.18), range 1,500 miles, speed 13/8 knots, armament 3 torpedo tubes and 1 q.-f. gun: (in commission) | 10 |
| Submarines of 200–300 tons (U.2.-U.8), range 1,000 miles, speed 12/8 knots, armament 2 torpedo tubes: (in commission) | 7 |
| Total Sea-going Submarines | 36 |