Divingdon:Are there many/any gaijin instructors working in Japan?
Yes there are. You should check in the ZEN divers forum. And speaking of which, perhaps this nihongo guide should also be moved to the zen forum...
The translations aren't too bad, a good starting point anyways. But remeber the golden rule of translations - to avoid looking foolish, always have a native speaker (in this case, a japanese) check it over!
gambatte ne