To put in context, 24,490 out of 39,000 U-Boat crews also perished – a loss rate of over 70%! - Rallye Driver
It was either Max Hastings or Len Deighton who researched and wrote: Highest losses in WW2 for UK were Bomber Command Aircrew, Front Line Infantry, Tank Crews and Merchant Naval Crews including military DEMS gunners (Defence Equipped Merchant Ships). - Hangarshuffle
The U-Boat casualty rate was nearer 85% if the 5000 who were captured are taken into account. The Royal Navy Submarine Service losses of 38%, compared with the overall Royal Navy loss of slightly less than 8%, are exceeded only by those of Bomber Command.
Jack