Kapok Schwimmweste Model 10-76 B-1
The Luftwaffe kapok vest was basically a sleeveless waistcoat consisting of yellow fabric rolls containing teased kapok, tied together by thick cord. Wooden pegs in front of the vest served to button all together. No pockets or other survival features are present, as the German Luftwaffe considered their live vests as pure floating devices.
The early models (10-76 A) featured an integrated collar providing buoyancy for the head. Unfortunately this layout had a tendency to make the wearer rotate in the water, especially if he was injured or unconcious, resulting in a face-down attitude. Many airmen downed over water paid the ultimate price to this design flaw. The inflated Model 10-30 initially had the same weak point., which was caused by the intention to provide as much buoyancy as possible.
Following these experiences made especially during and after the Battle of Britain, the open back style kapok vest 10-76 B-1 was introduced in 1943 - "only", one might be inclined to say... This later type omitted the "sausages" at the back and featured additional fabric straps in front, in order to provide a tight and safe fit.
Despite its bulkiness, the kapok vest had the clear advantage of providing buoyancy even if damaged, as there was no risk of leakage. While the vest absorbed water for buoyancy, it dit the same with petrol, though - with potentially dramatic consequences for the wearer in case of an onboard fuel leakage and following fire.
It seems that the Germans left the choice between kapok and inflatable vests to the aircrew. Photographic evidence proves that kapok vests were worn by all trades of Luftwaffe pilots, including fighter pilots in their cramped Bf 109 cockpits.