UB (ex HMS/m Seal)
Seagoing minelaying U-boat type of conventional design developed in 1930
| Surface/submerged displacement: | 1770/2113 t |
| Overall length/beam/draught: | 89.31 m/7.74 m/5.18 m |
| Standard main armament: | 6 bow torpedo tubes with 12 torpedoes and 50 moored mines on rails in upperdeck casing |