We rented a clam shell in case we needed to escape from the sun and sunburn. But it was way too hot to sit inside the shell, you needed the breeze! I wouldn't rent one again. If I did this cruise again, I would stay on the ship instead of going to the island unless you want to take part in any of the water sports.
Took the local bus to Palm Beach and got off at the stop near Playa Linda Hotel. We walked thru the hotel to get to the beach. You can walk along the beach or along the sidewalk next to the beach that connects all the hotels and bars. Plenty of great places to eat, drink & shop.