Snakes are plentyful here on Ambergris however unless you are out looking for them you are unlikely to encounter any.
If you doubt this just ask the guys who clear lots of land they see lots of snakes
There are Boa Constrictors that are very easy to find also Racers which are extrmely fast, there are garter snakes also,but based on my knowledge there are no poisonous snakes here on Ambergris.
Don't worry about Snakes you most likely will not see any but if you decide you would like to see some give me a call :-)
Have a great trip
regards
Gaz Cooper
Gaz Cooper's DIVE BELIZE
www.divebelize.com