I have spent a good deal of time in Sri Lanka and done many dives there. My wife is Sri Lankan.I've just finished getting my Dept of State Med Clearance, and I start the various training classes in April. By the time all is said and done, and by the time I spend some time w/ my family prior to deploying, I should be looking at a late June, early July start date.
I've done a ton of research, and am pleasantly surprised by the tremendous amount of diving I can do in the local area. Sri Lanka has a lot of dive spots, along with some really neat natural attractions above water. The maldives are an hour flight, Thailand and Bangkok are less than 4 hours away. For the next couple of years I plan to hit all of them at least once.
You're going to love it. All my dive (and topside) videos from Sri Lanka are here: http://www.vimeo.com/user2999552/videos/sort:date
A great site for your dive research:
These guys are new - the only dive op in Colombo, and fantastic:
And I highly recommend this op down the coast a ways:
I'm so jealous you get to live there. One day I'll do the same. All the best.