Convert Between Kriegsmarine Grid & Lat/Long (covers ENTIRE WORLD)
This may be old news, but I could not find a specific reference to this website here at Subsim. I ran across this webpage that can convert between Kriegsmarine Grids & Lat/Long and appears to cover the ENTIRE WORLD. First one I've seen that is this extensive. Check it out!
http://grid.nylle.de/find
In addition to a first-class conversion program, the author provides some excellent reading on the analysis performed in the development of the program, along with a discussion of the grids that cannot be tested due to a lack of available charts (although almost all these grid areas fall on land). Very nicely done!