If you want to do horseback riding there is a shorter tour in Grand Cayman. You can do a 1-1/2 beach ride which is incredible and yes romantic, you can even book a private ride if you want to be along. We did it for our honeymoon and they even picked up a bottle of champagne for us and we paid for it when we got there. The ride was wonderful and the operator was extremely friendly and she had very well trained horses.
We found them listed on the Cayman Islands Discounts site, caymanislandsdiscounts.com , they are listed in the activities section.