We are visiting in April and want to do a few of the trips (cave tubing, a few snorkeling trips, maybe a sunset cruise.) It seems like the hotel prices are higher than the local tour companies, so we thought we would just plan when we get there. Can anyone suggest a good company? We saw Excalibur and Monkey Business Travel Shoppe online and both had good prices. Does anyone have any experience with them, or can you recommend another place? And..... can we plan there or should we call ahead and plan our trip beforehand?