has anyone ever went outside of the carnival excursions and booked directly with a visitor's center in grand turk?  we are interested in the Horseback Ride & Swim excursion, but it is not offered to us from Carnival for the date/time of our trip (July - Elation Cruise). 

 a lot of private vendors on islands are under contract with the cruiselines.

Means:   if they have a contract they cant take you on as a private party-  you would have to book with the ship.

What nearby beach did you go to, how much was the taxi ride and what was the beach like?