| Submarines of 1,000–1,500 tons (“F” class), range 6,000 miles, speed 20/12 knots, armament 6 torpedo tubes and 2 q.-f. guns: (nearly completed) | 6 |
| Submarines of 800 tons (“E” class), range 5,000 miles, speed 16/10 knots, armament 4 torpedo tubes and 2 q.-f. guns: (in commission) | 19 |
| Submarines of 500–600 tons (“D” class), range 4,000 miles, speed 16/10 knots, armament 3 torpedo tubes and 1 q.-f. gun: (in commission) | 8 |
| Submarines of 300–400 tons (“C” class), range 1,700 miles, speed 14/9 knots, armament 2 torpedo tubes: (in commission) | 37 |
| Total Sea-going Submarines | 70 |
It must, however, be pointed out that six vessels of the sea-going “F” class have not yet taken their place in the active flotillas; and that eight vessels of the “E” class were on duty on foreign stations when war commenced.