Our group of 9 (all ages) did the Bob and Elvis Party Bus (email@example.com). It was a lot of fun. Good price with open bar on the bus. Our driver, Troy was great!
They took us on an informative tour and then to a beach. I think it was South Frigate Bay. The price included a beach chair and a drink at the beach. We rented an umbrella for $5. I had the best pina coladas I've ever had! Bring water shoes. It's rocky, but I heard from people that went to the more popular beaches that it was the same way, but also really over-crowded. We had the beach to ourselves.