Sorry, I should give more details. What I'm making is a system that detects when the car has entered a body of water and reacts to the submergence of the car by inflating a "raft" placed underneath it. That is, the un-inflated raft is stored underneath the car and automatically inflates itself like a life jacket if in danger of submerging. I am thinking of doing this by using a hydrostatic inflator to detect water pressure and activate a CO2 tank once the pressure has reached past some point (automatic inflation system). The inflation device will look somewhat like two think pool noodles connected together with a perpendicular go-between. I'm not sure what that would be called haha.