We used hotels.com to book our 1 night boat trip in Halong Bay. A bit skeptical at first, we confirmed everything over the phone and it worked out well. The company was very professional, and the boat was nice with 10 cabins, an eating area and a sundeck. Meals are included (except drinks), and they serve a ridiculously large portion of fantastic food. Rooms were very comfortable for a boat. There was surprisingly wifi, but it didn't work all that well (understandable; we didn't expect there to be any).