We are sailing on the Glory Oct. 14th to the Eastern Caribbean and then staying on the Glory to sail the Western Caribbean Oct. 21st. We have visited the ports on both sides before. Yes, it is less expensive to book off the ship. There is a down side to this. If you are late getting back to the ship when she sets sail, the are not required to wait for you if you did not book a tour through them. However, very seldom does this happen since most tours are aware of the departure time of the ship. I took a taxi to a beautiful park with a blue lagoon and snorkling the last time in Coszumel. There was three of us and it cost about $4 a piece plus the cost to rent snorkel equipment which was not very much. My husband went deep sea fishing on a tour through the ship which was not cheap. $145. Belize has some good tours to the ruins. Costa Maya has a reasonable tour (not through the ship) to horseback ride through the jungle/rain forest. Island Marketing is the name of the tour group. It was mentioned on this site (Cruise Addicts) They are suppose to be a reasonable and dependable company. I cannot say for sure because I have never used them but am planning to this time. Have fun on the cruise and good luck. Any other questions I can help you with, feel free to ask.