[Jimbuna]

Yes. This website: http://www.ubootwaffe.net/quadrant.cgi will translate between grid squares and lat/long coordinates. That being said, don't bother yourself with chasing after the ships in those messages. While those messages are historically accurate and were indeed sent on those days, they don't exist in the SH3 world (with some exceptions of major battles, etc.) So don't plan on beating Lemp to sinking the Athenia or anything.

Precisely