Just as a curiosity, the pilot license exam can be taken in Germany in either German or English language. The German one gives you access to all airports, while the English one just to English-speaking airports. While I'm pretty sure most tower operators speak English, their airport might not be listed as one, so you can't land there normally if you don't have the proper language exam. This might not seem like a big deal, but on these small airports you have a parking fee of about 15 EUR per day while on something like Frankfurt Airport the parking/landing fee is really prohibitive. Busy airports are also likely to request you to do really tight maneuvers in order to optimize the airspace, which might be tricky to do with a small/old airplane.
Actually English is mandatory for the aviation exam, it is the official ICAO communication language. If you don't have the aviation English exam, you will not be able to fly abroad and to the larger airports where the majority of the communication is in English. May not be an issue for ultralight pilots or similar that stay around their home club, but most pilots take the English exam anyway.
If for nothing else then for your own safety - that big 747 on approach flown by a foreign crew may not understand from your German/French/.../etc chat with the controller that you are on a conflicting trajectory, so they will have no spatial awareness of you unless the controller tells them where you are (few small planes carry TCAS-capable equipment). Which they should, but the controllers are only people too and can forget, be overloaded or just miss something, especially a small plane. This has led to some near misses and even accidents in the past and is the primary reason why English is mandatory today as the communication language in aviation.
I am pretty sure that one can fly to a German general aviation airport without having the exam in German language, only with English. Otherwise no foreign pilot would have ever been able to fly to Germany outside of the big airports.
Here is the list of what you will have to learn/obtain for a German private pilot license:
http://www.aerotours.de/en/lapla-leichtflugzeugpilot-699.htmlAnd actually Wikipedia has a good summary of what you need for the radiotelephony license:
https://de.wikipedia.org/wiki/Sprechfunkzeugnis_(Luftfahrt)#BZF_IFor a private pilot license you need at least the BZF1 or 2. The testing is done in German but there is a part where the candidate must demonstrate English communication capability, unless doing only BZF2 exam (German only, but then not allowed to fly outside of Germany. Commercial pilots must have BZF1 including English).
Then to actually be able to communicate in the given language the candidate needs also a separate language proficiency certificate (ICAO-4 level or higher).
The list also shows that there
is no HAM license prerequisite for the aviation radiotelephony certificate.
I didn't search for the marine radio requirements but they are most likely similar.