In 2019 Hurricane Dorian nearly cancelled a cruise I had booked. It was shortened and delayed from a 4 day to a 2 day, and had the option to cancel with full refund. That's what I did, and rebooked it for a few weeks later. Luckily I had that flexibility. If you book a Caribbean cruise during hurricane season, you need to be willing to either have that kind of flexibility, or accept that your vacation may end up cancelled. I'm sure you will not be cancelled, as that generally only happens when a storm is bearing down on a ship's home port. But these things happen. Avoid summer/early fall if you don't like the possibility of hurricanes disrupting your plans.