Belize is one of my favorites. Nice and warm, they speak English, and they use the Dollar (2 Belize $ to each US $). The Cays are absolutely beautiful, and it's not too expensive. We stayed in Belize City at a B&B, Chaa Creek Lodge in San Ignacio (
www.chaacreek.com), one night in Dangriga (yuk...), and for about 3 days in a beachfront cabin in Placencia (Kitty's Place), and a couple of nights on Laughing Bird Caye just off the coast of Placencia.
I really liked my time there (the 10 days before Hurricane Mitch which forced us to leave), and can't wait to go back...
http://www.travelbelize.org/
Bonus: They DO have a ski lake in Belize. I don't know if it's up and running yet, but you might want to give them a ring or an E-Mail
www.waterskibelize.com