compact and light weight deployable flotation devices with improved elasticity , tensile strength , shear strength , and puncture resistance using higher quality materials and sequencing of layers of polymer coating with greater mechanical strength in outer layers , and improved impermeability to gas leakage from within . the flotation devices are folded in containers with the containers having an integral gas supply cannister for use in a vehicle or vessel and for portability . the flotation devices are deployed by inflation by means of mechanical pull cord , automatically by float switches , hydrostatic release , electronic panic buttons , or switches used with a pyrotechnic release valve mechanism , or by pyrotechnic inflators . restraining mechanisms form part of inflatable bag construction for permanent mounting in a vehicle or vessel . a protective cover enshrouds the inflatable bag and its integral restraining mechanism , the shroud being able to expand at the end of bag inflation .