St Thomas - Trunk bay on St john's (you need to take a ferry or book through the ship)
St Maarten is often discussed here as the "suggested" beach - Orient Beach has a clothing optional section, so the "family beach" part is questionable. Use the "Find" tab above and search on St maarten beach for more info.
I have done St. Thomas several times. Wait till you get off the trip tell the cab driver how many in your party and where you want to go. I told him we wanted to see the island hightlights including magan point and magan bay. We dropped a couple off at magan point beach and continued on the tour and then he dropped us off for shopping down town. He will fill the van up and price you according. I think $20 or 25. I have done this 2 or 3 times. In St. Martin I did the Golden Eagle Catamaran excursions and loved it. I am going back in May and inquired about the beach as well. I will have a 8 yr old with me. I will skip Orient Beach because of the clothing optional thing. However, I did hear that Marigot which is on the French side with Orient Beach is a beautiful place and has lots of little shops and restaurants. I inquired about other beaches to take my daugther to. I was advised that the beach right off from where the boat is which is the dutch side is family oriented. So we are going to take a taxi/van site seeing through the french side and spend a couple of hours shopping and looking around and then taxi back to the beach close to the ship. This will be on our own, not through the ship excursions. I looked at them, but most of them were only site seeing or included orient beach and I don't want to take the little one, so I decided to do it on my own. We are going on the Liberty of the Seas on May 24th. Hope this was helpful.
Actually, the snorkeling is better in Sapphire Beach, but getting into the water is much better in Coki beach. Sapphire has a lot of rocks at water's edge, the north end has fewer, but if it's a calm day, the snorkeling is great. You have to try it next time you're there Cortney. Coki and Magen's have much better ammenities, so Lid4 if you want to stay on St. Thomas, those would be the two best choice beaches. Trunk Bay on St. John is absolutely awesome. Scott Taylor also took a catamaran sail/snorkel to Honeymoon Bay out of St. Thomas and he said that was fantastic. St. Maarten-if you don't have children Orient Beach. Marigot or Maho if you do. There's a beach close to where you dock and a nice shopping area. We did the America's Cup Racing Yacht excursion the last time we were there and it was a blast for all ages. Best wishes!
We usually use Shoretrips.com or other private contractor. Caution: watch for references on this and other sites, or from people you know. A pretty webpage does not make someone honorable. Shoretrips.com is US based and has insurance (like if the boat breaks down to get you to your ship, for instance, kind of important). They have been in operation over 7 years and no customer of their has missed a ship. Incidently, I am not affiliated with them or the travel industry--just a really happy customer. Private contractors tend to have smaller groups than the ship, some are also cheaper--but for the same $$ I just like the smaller group.
RCCL Nordic Empress 1993
RCCL Nordic Prince 1994
RCCL Explorer 2003, 2005
RCCL Navigator, 2004, 2007
RCCL Mariner 2006
RCCL Liberty 2008
RCCL Adventure 2009 Read and post cruise reviews