While there are many a beach where you may ride, it is my understanding that it is now forbidden on Negril Beach because of the horsey poo factor. A handful of years ago a 'vacation date' of a friend really wanted to do it and managed to convince some boys to provide a horse just before dawn provided that she pulled a Lady Godiva. They of course then had to follow her (merely to collect any samples left by the horsey they assured her).