An underwater motive device provides an integrated and modular battery and motive housing which is carried within an outer housing and secured by a nose cone system. The nose cone system works against an "o" ring seal carried between a structure of the integrated and modular battery and motive housing and the outer housing. A pair of latches act as levers to forcibly push the nose cone in place to seal off the battery compartment, and with cam action when used to urge the nose cone to a disengaged position with respect to the "o" ring seal. Nose cone removal and re-sealing procedure can be accomplished easily, even by those of limited strength.