The Carley Life-Raft, or Carley Float is a form of collapsible, reversible life raft patented by Horace S. Carley in 1899 & 1902. Buoyancy was provided by a oval or capsule shaped frame made of tubular sheet copper, sheathed with cork. The copper frame had internal watertight dividers, providing additional subdivision, but primarily as strength members. The cork was held in place firstly with wire, which was then wrapped in wire cloth and a heavy canvas. The canvas was then painted with waterproof paint. From this ring, a rope webbing held a wooden grating, which served as a platform able to pass through the ring (hence, reversible).
Carley floats were virtually unsinkable, the robust metal frames being well protected from damage and the cork being intrinsically buoyant. As a result they were used extensively by a number of Allied nations, particularly during World War II, where damage from shrapnel or munitions would not render the float inoperable. The floats were available in a number of sizes, which could be 'nested' in eachother, allowing 2 or 3 floats to be stored flat. Warships and merchant vessels could quickly increase their lifesaving capacity by mounting sets of floats on exposed decks or bulkheads, with only a few tie-down points required. They were durable enough to withstand the elements & light enough to be thrown overboard when needed.