Abstract: The principal element of a rescue equipment for submarine vehicles includes a principal gas generator in which hydrazine is forced through a catalytic reactor causing the hydrazine to decompose and the developed gas is used to blow a ballast tank. The hydrazine is moved into and through the reaction chamber by operation of a second pilot gas generator likewise operating on the principle of decomposing hydrazine and being operated in a regenerative feedback fashion through a differential piston arrangement so that upon an initial triggering the gas developed by the pilot gas generator drives the differential piston so that increasing pressure is available for driving auxiliary hydrazine through the reaction chamber of the pilot gas generator until a stable operating point is attained. This operating point is automatically adjusted to the effective water pressure against which the principal gas generator has to operate to thereby render blowing time of the ballast tank independent from the depth of the vehicle.