Posted By Elliot Morton Hi, As we work in marine civils and dredging we use auto inflating 275 newton twin chamber units ( also 150n and 200 n units) which are less cumber some to work in, we work in coastal water or at sea and also have a rescue boat on stand by you also have Maritime and coastguard agency / UK SOLAS (Safety of life at sea) these are the sort you find on ferries and cruiseliners. they have to pass tests to be certificated for commercial use. then you have bouyant workvests that are used for still water likes ponds or canals these are all available from marine chandelers regards Elliot