As in Ha Long City, it's easy enough to book a boat trip out of Cat Ba Island to explore the Bay, either with a travel agent or direct at Beo harbour, 2 km from the centre of town.
Photo of Boat trips around the Bay    

It's probably a better option than Ha Long: you're much closer to the action on Cat Ba so there's less time spent getting to the pretty bit. Also, tours explore beautiful Lan Ha Bay, which you won't get to if travelling from Ha Long City, unless you're out for three days.

You can also book two- or three-day trips around the bay or get a boat out to Monkey Island – for some beach time – or with a stop to cycle to Viet Hai Village.

Travel agent prices range from $10 to $25 for a day trip, depending on route. You won't save