Thank you!
However, I still didn't find the right tool. The tools I find are labeled "tool helper", "ruler", "eraser", "protactor", "zoom in", "compass" and "marker".
I may be really stupid, but what does it look like? I used the (navigational) map by pressing F3.
This is what my map looks like:
https://imgur.com/sWpSijK
As soon as I figured this out, I'll go ahead and buy the U Boat expansions. I already saw the "Operation Monsun" mod, which appears to model all German submarines and submarine operations during WWII. Basically enough to replace SH5 (which still has performance issues for me). Thankfully, I installed Steam, along with all its games, in a separate folder already.
I was asking about the automatic targeting, but I guess I'll figure it out myself as soon as I manage to leave Pearl Harbor
But I'll surely dive into the TDC at a later point.
Best,
Brett