Sorry, wrote my post before I read the second part. You can book your own excursions that will refund your money if you don't get into port of if it needs to be cancelled due to weather. Our excursion in Grand Cayman is 100% refundable (Bucaneer Catamaran) if we don't make it. Key West, we pay when we get there (BOB's), and Cozumel, non-refundable, but goes-RAIN or SHINE (Dune Buggys)!!! I know many are run this way, but many others are not. Best to double check before booking your own.
Mrsfuzzmo