Yep. Those U-Boats were a ticket to death, I believe over 1,000 sunk and over 30,000 sailors went down with them. Nasty business. I suppose that movie Das Boot did a pretty good job of exhibiting the anxiety level of any submariner, on any side of the war.
Later in the war the Allies’ improved tech and methods enabled them to take out German subs like there was no tomorrow.
US subs were at a huge disadvantage early on (until late 43) because the torpedoes were garbage and the Bureau of Ordnance refused to fix them. Fortunately Japanese ASW tech was terrible else the subs would have suffered far worse.
I took a tour of a Gato class sub when I was in the Navy in 1968. They are nothing like the movies inside. No way would I ever volunteer for those things. My hat is off to those guys. And the aircrews in WW2. Balls of chrome plated steel.