Good Morning Cat Ba offers daily buses from Ha Giang to Cat Ba island and vice versa, and the total travel time is about 10 hours.
The journey is a combination of a tourist bus and a limousine bus. First, you will travel by limousine bus (12 seats) from Ha Giang to Hanoi, and continue with a 34-seat car from Hanoi to Cat Ba island.
The distance from Ha Giang to Hanoi is about 320 km and about 6.5 hours. Meanwhile, Hanoi to Cat Ba is about 160 km and it takes about 3.5 hours.
The bus will stop twice on the way for you to rest and grab some food for lunch and diner. You can book tickets online here.