Yes - used Dolphin Water Taxis last summer for a transfer from STT to TMM Marina - via Customs Clearance. Very efficient. They met us on arrival at STT - taxi transfer to Red Hook, then immediate departure to Tortola. The stop for customs clearance was very brief - no doubt helped by the fact that there wasn't a Ferry clearing in at the same time. Then they took us round to the TMM Marina at Road Reef. For the return they showed up at the TMM Marina on time, and we went straight to the Customs hall at Charlotte Amalie, then a taxi the short distance to the airport. Its a very good service. We were a large group of 15/16 people - and it was certainly expensive I remember, but it saved a lot of hassle and waiting around! Would do it again if I came through STT.