I was on a cruise about two years ago, and Mahogany Bay was one of the stops. Once you walk uphill past the shops, the walkway takes you back to a large area that has a beach and quite a few drinkning establishments that also serve food. If you don't want to walk that far, you can catch a gondola type mode of transport (2 person chair), that rides high over everything to the end of the island. Once there, you can enjoy a beach, or some of the very loud music that is blasting from several different bar/restaurants.
As usual in most ports of call, there is plenty of shopping, drinking spots, and eating spots.
As avid cruisers, we found Mahogany Bay to be one of the more interesting stops.