Perhaps the first commercially available life jacket was the Mallison Seamans Friend which was advertised for sale as early as 1804. The modern life jacket, a cork vest, which was worn by life boat crews, provided flotation and protection from the weather. A Royal National Lifeboat Inspector, Capt Ward, introduces this vest in 1854.
The life jacket took another leap forward when pouches containing watertight cells filled with
a vegetable material replaced the rigid cork material. These soft cells designed jackets were flexible and more
comfortable to wear compared cork jackets.
Kapok buoyancy was used in many navies fighting in as late as WW II. Soon foam would replace the Kapok in life vest.