Just to clarify a couple of points about air-sea rescue during the battle: for the British this was one of their weakest links and biggest oversights because there was no real a/s rescue organisation set up - British pilots and aircrew who ended up in the 'oggin were lucky if they either landed near a convoy and were picked up by a passing ship, or were close enough to land to swim ashore, or close enough to one of the German rescue buoys - otherwise they were often left to their own devices -according to this:
http://www.telegraph.co.uk/history/w...f-Britain.html
maybe 200 pilots were lost because of this failure. According to Stephan Bungay
The Most Dangerous Enemy: A History of the Battle of Britain even the issue shirts worn by British pilots and aircrew (made by Litchfield) were a liability because the collars would shrink when wet, possibly helping to strangle the poor wearer. In addition, the issue "Mae Wests" were not self-inflating and it was well nigh impossible for someone who was injured or in shock to have the strength to inflate it. Of course, on top of it all the normally cold water meant hypothermia could set in very quickly.
By contrast the Luftwaffe was highly organised, with Seenotdienst air-sea rescue units, properly equipped rescue buoys and reasonable life jackets and life rafts, and all aircrew carried sachets fluorescein which created a large, easy-to-see, bright green patch when in contact with water.