depends on what you like to do...
When we did our western..we didn't plan any group excursions
because it was our first time to the islands so we wanted to have plenty of time to look around.
In Grand Cayman..when we got off the ship we grabbed one of the taxi vans for a two hour taxi tour of the island..it takes you by all the famous places, lets you out to look around, take photos and shop. It was excellent..we went to hell, turtle farm, he stopped at one of the beaches for us, etc. Then he dropped us back off near the dock for shopping. Well worth the price he charged...I want to say $20 or less per person..and we tipped him of course...he was very funny.
You can purchase and mail postcards from hell to your friends and family back home. The turtle farm is wonderful..you can hold the sea turtles, pet them under the chin..lots of fun. One of the many tortuga cake factories is right beside the turtle farm..so the smells coming from the bakery are wonderful. The cakes themselves are wonderful also..lol. You can also sample the tortuga rums..yummy.....but, the only place you can purchase them to take back on the ship is that little store...looks like a small house..right at the dock...customs rules in Grand Cayman for alcohol..stricter than Cozumel. You can get some of the tortuga flavors on the ship..not all.
When coming back through town..we noticed microbrews on the oceanside..not far from the dock..(restaurants also). So we walked up that way to get lunch and try the beers..all excellent.
The furthers is rackhams, they have the Grand Cayman stingray beer and a great souvenier shop and a wonderful menu.
The second is big bamboo..5 microbrews to try...they grill fresh fish for you on the deck..also wonderful. Both had wonderful people, the bars are outside, overlooking the ocean..a great place to take a break before shopping..lol.
There are big pirate statues all over the shopping area..they make for great photo opps. There is also Hard Rock Cafe right near the dock.
In Cozumel..we had a great time as well. From the recommendation of people who had cruised before us..we got off the ship when it docked and grabbed a cab straight for mr sanchos beach area. It is wonderful...we had planned to have lunch there..because previous cruisers said the food was great..adn it was. You can check out all they have to offer at mrsanchos.com. We spent about three hours there, then headed back to the shopping area. We had the taxi driver drop us at the far end...forum shops..because hubby wanted to check out the cigar shop upstairs in the forum shops. Nice cigar shop, great little bar to have mojitos in, which was just perfect after the beach. Then we went downstairs to look at the jewelry..and pick up our free tanzanite and diamond earrings. Of course..I picked up a little something for myself as well..lol.
We continued shopping...we really liked the cinco soles store...large and there is no negotiating involved..everything is price as marked. Checked out a bunch more shops..found the hard rock of course, went to the grocery store for vanilla and tequila, took everything back to the ship..freshened up and came back out for dinner. We had a wonderful dinner at carlos and charlies..what a great place. Right across from the dock, open in the front, just beautiful to look out in the evening when the ships are all lit up.
Enjoy!