J-class submarines
J-class submarines statistics:
| Number completed before 1919 | 7 |
| Number completed after 1919 | 0 |
| Lost in action | 0 |
| Lost accidentally | 1 |
| Prototype date | 1916 |
| Surface tonnage | 1210 |
| Submerged tonnage | 1820 |
| Length | 275 feet |
| Engine | Diesel |
| Horsepower | 3,600 |
| Screws | 3 |
| Surface speed | 19.5 knots |
| Submerged speed | 9.5 knots |
| Torpedo tubes | 18 inches |
| Number of torpedoes tubes | 6 |
| Guns | 2 x 3 inches |
| Crew | 44 |
