I'm going to Cozumel in September and our time in port is 1pm-10pm. I am looking at booking excursions and am frustrated that most excursions are before 2pm. All of the excursions over 3 hours that I've seen leave before noon, so they are automatically eliminated. Most of the snorkel tours do their last run for the day at 2. This would probably be hard to do with the ship not even coming into port til 1. Do tour companies adjust their times based on when the boats come or am I forced to book through Carnival?

When you get off the ship in Cozumel there will be a million and one tour operators there to take you to do what ever you want to do! Just be sure that your within a quick drive back to the port within a couple hours of departure time! You'll save 50% or more by getting the excursion off the ship! Have Fun.

Are you taking into consideration the time zone difference?  If you're sailing from Florida, the ship will be on Eastern time (as will all the times shown on the itinerary) but Cozumel is on Central time so is actually an hour behind.  Sooo, when you're itinerary says you arrive at 1, it's actually noon by local time.  Be SURE to remember this at 9 pm!!