I'm going on a Western Caribbean cruise on Aug. 19. I have a question about going on shore excursions. I plan to go snorkeling so what should I wear when leaving the ship? Do you wear casual clothes, such as shorts, and bring bathing suit along? Is there somewhere to change? I have a beach tote bag that I can carry all of my stuff in but when you get to Stingray City or wherever, is there a place for you to lock your stuff in, such as a locker?