Abstract: A flotation device for providing emergency flotation for a person swimming or passing through a body of water, comprising a container filled with a charge of a gaseous material under a pressure such that it is in its liquid phase at normal environmental temperatures. The container is connected to a flexible flotation chamber through a passage which remains normally closed until actuated by the user. When the device is actuated by opening the passage, the charge expands into the flotation chamber, thereby inflating it, and providing support to the user in the water. The gaseous material has thermodynamic properties such that it remains in its liquid phase right up to the maximum temperatures to which the device is expected to be exposed to. Consequently, its volume, and hence the internal pressure within the gas container, does not increase significantly, thereby enabling the container to be of lightweight construction.

Abstract: An inflatable flotation device having a reaction chamber with reactants that generate gas when mixed, said reactants being separated by a barrier assembly; an activating mechanism adapted to remove or puncture the barrier assembly such that said reactants mix; and an inflatable compartment fluidly connected to the reaction chamber by means of a pressure sensitive passageway, adapted to open only when the pressure of the gas in said reaction chamber exceeds a predetermined threshold. This ensures that most of the reactants are used up to generate gas before the gas enters the inflatable chamber, thus preventing scattering of the reactants. Some implementations have a reaction chamber without a barrier assembly, comprising reactants that generate gas when mixed with water and an activating mechanism adapted to expose the reactants to water. A variety of manual or automatic mechanisms may be employed to activate the reaction and inflate the device.