Just wanted to share my latest for anyone considering doing the same. Spent a week in Belize mid-March this year. I am a 220 lber. Brought a 17m Slingshot Turbine, 14m Airush DNA and packed a small board for traveling --- 134cm. Tried Palencia, but beach is real narrow, winds were light ( barely above 10mph ) and I, not surprisingly, couldn't get it going with that little board. In the attempt to get away from shore, I clipped a palm tree and got my kite hung over it which gave some excitement to a couple of snowbirds.
Had better luck in Caye ( Key ) Caulker. It is a 30 dollar round-trip ferry ride out there from Belize City that takes about 40-45 minutes each way. If you have a rental car you can park right next to the ferry dock for $12.50 US ( 25 Belizean ) each overnight. All the posts I saw beforehand talked about launching/landing at the Split. The Split has a seawall you have to contend with so you are either going to be flying your kite whilst going down a ladder or launching in the water. There were stairs at one end of the sea wall, but they are just upwind from power lines. The launching area above sea wall is also small and competes with a volleyball court. In a nutshell... it is sketchy as hell. Even Kuba the local kite guy at KiteXplore just kind of shrugged his shoulders and basically was like... 'it is what it is'.
Well I decided to scout the coast a bit and didn't take long to find a better option. About 550 meters south of the Split is a beach in front of La Isla Resort. It is between Calle Aquado and Chapoose Street. There are piers on each side and you don't have much more than 50 meters between them. Water is shallow, though, so you can walk it out to end of the piers. Wouldn't recommend for beginners, as any kiting nears piers can get ugly if things go wrong. I self launched with a strap tied off to the southern pier's pilings. Once I got going, I worked it upwind to play near the Split. Once again I don't like kiting near piers, but for Caye Caulker, I would recommend dealing with them for the launching and landing as doing so at the Split just seems to be asking for trouble.
In my two days there, we never had winds above 15mph in the daytime, but it was enough for some fun sessions with the 17m and 134cm. Water is super clear and you get to kite with Stingrays... pretty cool.