The ones who did convoy duty to Murmansk would either refuse to talk about it, or they would be very grateful for the chance of 'unloading' some of the emotional turmoil.
(It was common that ships had orders not to stop or slow down to pick up survivors in the water if a ship was sunk. Everyone knew that there might be more subs or other warships lurking, but to hear the cries of those in the water, and not be able to do anything... )
The only one I know of in my family who 'fought' was my maternal grandfather.
He was the captain of a small fishing boat on the north-western coast of Norway.
(Not far from where I live today, actually)
He smuggled weapons and goods brought over by the 'Shetland Bus' and to the final recipients; the resistance fighters and agents.
(Watch the movie 'Suicide Mission' to learn about the Shetland bus and the risks everyone took. Captain Larsen was the most decorated allied naval officer of the war. )