Underwater Vehicle comprising at least one reception outer tube and launching a vehicle submarine

The underwater vehicle of the type comprising at least one outer tube (10) for receiving and launching an underwater vehicle (11), said tube being filled with gaseous medium for storing dry the underwater vehicle (11 ) prior to launch and has at least at one end a door through which the vehicle can be started, is characterized in that the tube (10) is associated with means balancing tank (12) containing a liquid fluid for during the preparation of the launch of the underwater vehicle, to be inserted into the tube (10) by driving means in the balancing tank (12), the gaseous fluid initially contained in the tube (10).