How about something like this:
I don't know the German translations, but what's important to me is not really the seas and oceans - I pretty much know whether I'm in the North Sea or the Atlantic. What I like to be aware of is the geography around me - if I'm somewhere west of the British Isles and the sea gets shallow in the area I want to know whether that's Rockall Bank or the Faeroe bank. I also want to know whether the islands around me are the Faeroes or the Shetlands.
I wish I could do the work myself, but Photoshop LE doesn't let me play with layers (the image just appears black in Photoshop). Maybe I should go out and buy a program that supports layer tweaking.