Heavy Duty South African style inflatable float. Designed and built by SpearMaster. It is a high pressure float designed to perform at 30psi. A 30 psi float (when inflated to max pressure) will maintain the same buoyancy to a depth of nearly 2 atmospheres.
Tested up to 30 PSI (2 bar) without failure.
Ask around, most every other inflatable float is only rated at low pressure, and will loose buoyancy at less than 1 atmosphere of depth.