Halong Bay is 160km from Hanoi, and takes 3.5 hours by bus. Usually half-way the bus will stop for about 20 minutes. The package includes lunch on board a boat that takes you round for about 3 hours exclusive of time taken to climb and see a cave on one of the limestone islands, and perhaps a stop at another island (T-top island?) for you to climb to the top and have a magnificent view of the Bay.