the system and method of the present invention provides an inflation device , such as a life preserver , that is automatically actuated by hydrostatic pressure . a diaphragm that is moveably responsive to fluid force created by fluid pressure actuates a first stage for providing a first force , that in response , actuates a second stage for providing a second force . the second force provided by the second stage is transferred by a force translation system to pistons , which in turn puncture co 2 cartridges . the punctured co 2 cartridges then release stored co 2 and inflate a previously deflated life preserver .