There is no airport in Bai Tu Long Bay. The nearest airport is in Haiphong City, which is about 60 km from the bay.
From Hanoi, take bus #79 from My Dinh bus station to the Bai Chay bus station. The bus ride takes about 2.5 hours.
From Hanoi, take a bus to the wharf in Halong City. From there, take a boat to Bai Tu Long Bay.
There is no public transport in Bai Tu Long Bay. Tourists can hire a boat to take them around the bay.