on the boat and it's easy. Don't go over 4 feet of water & you'll STILL see everything on that first (fish identifier) link, especially if you toss some cereal in the water.
What's your itinerary? If it's the ususal, here's the plan: shop in Mexico, unless you want expensive designer items. Do your beach/water stuff in Cayman. 100 foot visibility, like bathwater, usually very still. Do any beach biz in the a.m., as downtown Georgetown is a madhouse when the ships come in, shopping-wise, especially in the morning. Stroll around downtown for lunch & afterwards--less crowded. Get some Cayman coins (everybody takes US $ & gives change in US or Cayman, just ask) they're beautiful & make great refrigerator magnets. The stamps are cool too & the post office is a few blocks away from the harbor.Georgetown is not dangerous to stroll, btw. Cayman has a higher standard of living per-capita than the US.
Last (or first) stop is Jamaica, right? It is simply gorgeous--mountains, beaches, everything, except the towns. Lots of poverty. I find the Jamaicans to be very funny, friendly and extremely persistent salespeople. Don't pay the asking price for ANYTHING on Jamaica--if you don't bargain, you're a sucker there. Get a cold bottle of Red Stripe at a beach bar-- there will be a cricket match on the radio or TV (do NOT ask them to to change it. It's insulting & they won't do it, anyway.) and just kick back.
Unless it's a real doozy, don't book land excursions though the ship. You'll end up paying triple the real cost and feel like cattle. Get off the ship w/ your new cruise pals or just yourselves and find a taxi (they'll find you, actually). Make a deal for wherever you want to go, do, & see and for a return pickup to the harbor.
No worries.
Edit to add: Cayman weather, info, message board, discount coupons (good ones!) and webcam here:
http://www.caymanactivityguide.com/forums/General_Questions-forum21.htmlLooks drizzly today and those are big waves for 7 Mile Beach, honest! LOL