[Jon]

The early Luftwaffe schwimmvest Battle of Britain period, although compact and small to wear in the confines of a fighter cockpit had a major flaw in that, the back also inflated when the oxygene cylinder was opend. This caused a few pilots to drown because if the were injured or passed out the jacket forced them onto their fronts face down in the sea. Later German schwimmvests had the rear modified and this problem was stopped. I own a Battle of Britain Schwimmvest from a downed pilot in August 1940 and it still has traces of the yellow dye he used to indicate his position when in the sea, this was a great life saving factor and greatly increased the chances of another aircraft spotting you and getting help.

RAF Mae wests were very bulky but supported the head and neck in the sea, another big advantage of the RAF jacket was it could also support when damaged, the German bladder type simply would bleed air away.

By Falling into the sea around Europe and Britain i think drowning was the leat of your worries as the cold would kill you in minutes at certain time of the year and a few hours at the best.