Wakayama Scuba

I haven't used my scuba license (college gym class) in years, but I was planning on pulling out the PADI card to check out the whales in Okinawa island this wintr. Then I just heard about this crazy underwater mailbox in Wakayama. I think I might want to check it out.

Doesn't this sound awesome (if not completely wacky)?!:

Susami Kaichu Yubin-Posto (The Susami Kaichu Mailbox) can be found at a depth of 10 meters off the coast of Susami, Wakayama, and is certified asthe "World's deepest mailbox" in the Guinness Book of World Records ('02).Special plastic postcards (￥150 domestic, ￥350 international) are available, and divers mail nearly 200 daily in the summer peak-season. The mailbox is open from April to September, so if you're adiver and keen to post mail from deep in the ocean, now is your chance!

There is more info here http://www12.ocn.ne.jp/~noah-s/post.html (Japanese only), but it's also on Wikitravel.