Well done. My first swim was in Jan 64 and the water temp about 2. Even in the 70s they would not let aircrew that did not fly with immersion suits to use them although in very cold conditions they would.
One of my fellow studes had a dinghy malfunction. They left him for a few minutes to sort it out as he would have done for real (or died), then just threw him another one.
At least Mr Howarth' s death was not in vain as it formed the basis for greater stalling of immersion suits.