I've heard good things about the diving on Okinawa. Supposedly, there are many nice beach and shore dive opportunities there. Don't really need a boat to "get your fins wet" and at least see something, so to speak. Sounds like the Sinai or Maldives. Cruise on up to the beach, gear up, wade out and go under. Also heard there were some items from WWII still being found from time to time.
Heh, you are in a diver's paradise. Enjoy it while over there.
If you do indeed ever make it over to USAFE (USAF Europe), you'll find that despite the drawdown, there are still a couple of American SCUBA clubs over there. You really enjoy yourself more with the locals though. They know all the good places and party the hardest. You'll also find the fellowship and camraderie amongst European divers is greater than Americans.
To sum it up, Europe is pretty much like this: What little marine life in the Med you see, the Spanish, French, Italians and Greeks haven't shot, speared, stabbed, hooked, netted, bombed or polluted yet. In reality, the Med is Europe's swimming pool. With the exception of the Canary Islands, I found the diving off the south coast of France to be better than Spain. Portugal on the Atlantic side has some good sites. They just aren't well known. Great diving can also be found on the Adriatic in Yugoslavia, from what I've been told. Even during the cold war, the old Yugoslavian military had a deal for NATO members as far as lodging on the coast near some good dive spots. In Scandinavia, Norway with it's fjiords absolutely rules. Sweden and Finland have decent sites on the Baltic. However, I found it was hit and miss with the weather.
By far though, I found the UK the best. Wasn't warm or easy diving, mind you. But the obvious fact that the UK has been a maritime nation for centuries hints at what can be found there. I read once in a British magazine with the imaginitive name of 'Diver' about a conservative estimate of 70,000 wrecks off the coast of the UK. Many opportunities abound, particularly in the south off the coasts of Cornwall or Devon. In addition to Scapa Flow, Scotland has much to offer, particularly off the west coast. When travelling north to Scotland, the people seem warmer and friendlier the further north you venture. The sheer culture in the UK was what made diving there so enjoyable for me. The wrecks vary from sunken WWII Liberty ships, to the German battleships at Scapa Flow (nearly intact BTW), to the older wrecks in the Scilly Islands from the 1700s. Just awesome. With good vis, say 30-50 feet, the effects are incredible. On one particular occasion that I'll not forget, I was able to just barely see one of the battleships from the surface while diving at Scapa Flow. Truly breathtaking!
By the way, I subscribed to Diver for three years while in Germany. Really informative publication about local diving in Great Britain. Tauchen, although in German, also was packed with good info.
The Shetland Islands (UK) and Faroe Islands (Denmark) enroute to Iceland also have a couple of decent spots shielded from rough seas. There was a ferry from the UK to the Shetlands, Faroes and Iceland during the summer. I'd say there still is. Again, we are talking cold water with limited vis. Hardcore as hell! I mean diving at nearly the very ends of the Earth. I spoke with a Norwegian dive operator who told me Iceland had some interesting places also. Definitely drysuit time.
Some day, I'll go back to Europe for four months just to dive. Start in south France or Italy, or maybe even Turkey during May and try to hit the UK and Scandinavia in July/August.
<edit>edited for clarity</edit>