Victory at Sea: IJN Submarines & MTB sectionsSubmarines: The Kaidai 7 class, or KD 7, was developed in the late 1930s, following on from the preceding KD 6 class. With a surface range of 8,000nm at 16kts, and a submerged endurance of 50nm at 5kts, they possessed a slightly better underwater performance to the late model KD 6s and better surface speed (though not range) than the earlier members of that class. All members of the class were lost by mid 1944. Another ocean going submersible using