There are direct buses from Halong Bay to Ninh Binh, including
public buses and private buses, which may include open ticket bus
There are many private bus companies operating to and from Halong
Bay, but most are working with tour companies and there are no bus
company offices or travel agents in town. Try going to the
tourist jetty, 2 km west of Bai Chay (an easy walk) and ask around.
There is a travel information office there that might be able to
help. There is also a guy from the Thong Nhat Hotel, just
opposite the post office in Bai Chay, who can sell tickets to Ninh Binh
(150,000Dong, 4 hours) for a morning and afternoon bus. You need
to book a day in advance the bus needs to be informed to collect you
from the Thong Nhat Hotel. This guy can be found at the hotel or
at the tourist jetty.
Public buses leave for Ninh Binh from the Bai Chay bus station,
which is 5km outside of Bai Chay. Alternativaly get a motorbike
taxi to drop you by the bridge intersection of the highway, from where
you can flag down a Ninh Binh bound bus. Buses to Ninh Binh take
3 hours and cost 70,000Dong.