I am sailing on Western Caribbean so Falmouth, Cozumel and Grand Cayman. Are you allowed to grab a taxi to another destination and not return to the ship with your excursion group? For example, if I do a 2 hour snorkeling tour in GC, can I head to the beach after? Or if I want to shop at the port, can I do so after the excursion or do you have to get on the ship and then get back off?