During the Second World War the Luftwaffe deployed a series of rescue buoys or Rettungsboje along the Continental side of the English Channel. The buoys were intended to provide shelter for downed airmen until help could arrive.
There were several similar buoy designs employed in this effort. Luftwaffe aircrew called them Udet-Boje after Ernst Udet, who directed their development. The British nicknamed them “lobster pots” due to their box-like shape and bright yellow paint schemes.
This contemporary magazine illustration shows the internal layout. The buoys were provisioned with food, dry clothing, medical supplies, and various means of signaling the need for rescue. There were also basic creature comforts such as playing cards, radio, and board games to alleviate boredom. Supplies were to be immediately replenished by rescuers to ensure the buoys were always fully equipped and ready for the next use.
The buoys were not secured in the typical manner using multiple anchor points and chains, but were moored using a single anchor line so ditching aircrew would have a visual indication of winds at the surface and could ditch their aircraft in a favorable position for the crew to reach the buoy. Consequently the buoys would occasionally part their moorings and wind up washed ashore like this example.
Retrievals were often performed by dedicated rescue aircraft of the Seenotdienst, the Luftwaffe’s rescue service. Here is a Heinkel He 59 in a high-visibility rescue scheme. These aircraft were suspected by the British of performing reconnaissance in addition to their rescue duties, and the RAF was ordered to consider them legitimate targets.
Seeing the value in the concept, the British developed their own version which was deployed along the English side of the channel. With a more boat-like hull, perhaps seakeeping was marginally improved.
Many aircrews were saved by the buoys on both sides of the Channel. For their parts, aircrew in distress took their chance for survival and used what ever rescue buoy they could reach, only the identity of their rescuers determining whether they would be held as PoWs or returned to their units.
A short but very well-done video description here: