A friend rented a ski bob at the beach near the dockyard...does anyone know about this? How easy is it to get to beaches and Hamilton from the Dockyard if you don't book excursions through RCCL?

Very easy. Bermuda has a good bus system, which you can purchase passes for and get all over the island. You can also rent mopeds, or take a cab.

andthey also have a water taxi which is fun just to go to the different places, then take the bus back for a different view. Bermuda is beautiful, enjoy! The ticket windows are right where the ship docks, and then you walk up the pier to where you get all transportation.