Supplement to SH Survey: What should Ubi do to make SH5 the best?

[Sea Hawk]

Originally Posted by Contact

Could you please give us a link to this fact where german u-boats were attacked by friendly fire ?

Ive been reading the book "The Underwater War 1939-1945" by Commander Richard Compton-Hall MBE, RN (Ret'd) 1st published in 1982. I bought it from a second hand book shop.
It mentions the following:-

In 1939 HMS Triton and HMS Oxley encountered each other off Oprestad with the result that Oxley was sunk.
4/5/1943 U-439 and U-659 collided while pursuing a convoy and both sunk.
Jan 1945 HNMS Dolfijn was fired on by an RAF Mosquito ending the war for her.
11/11/1942 HMS Unbeaton sunk by RAF aircraft.
HMS Unison fired on by a "friendly" ship while travelling in convoy.
29/5/1958 USS Stickleback rammed and sunk by USS Silversteen

"Submarines of World War Two" by Erminio Bagnasco published 1972 lists the following as sunk by "friendly" forces

Germany
Type VII U-235 Baltic 1945

French Perle Atlantic 1944

Great Britain
O Class HMS Oxley N Sea 1939
U Class HMS Umpire N Sea 1941
U Class HMS Unbeaton Atlantic 1942

Italian 600 class Topazio Mediterranian 1943
Italian Perla Class Gemma Med 1940

USA
R 19 (as P514) Atlantic 1942
S 25 (as Polish jastrzab)Atlantic 1942
Sargo Class Seawolf Pacific 1944

The list above shows the subs final fate and does not take into account the number of "friendly" fire incidents which did not result in a sinking.
All in all Germany did pretty well in respect to "friendly" fire. The Brits had more aircraft (fewer subs), the Germans more U-boats, so it was not surprising that the RAF mistook submarines, most of the subs that they saw would be U-boats.
"Friendly" fire incidents perhaps should be modelled if SH5 includes British subs but is not as much an issue for U-boats.