Lamanai is by far the best Mayan ruin tour,the only one with artifacts on display in a field museum.It also has monkeys in their natural rain forest setting. I always suggest it for the birdwatchers who request birding trips. largest chance of seeing Toucan and Jabaru Stork.
The front desk of your hotel will book it for you all the operators are good.

White Sands Dive Shop
https://whitesandsdiveshop.com/