We had the two-day experience in the bay with Mila Cruise. Transportation organized from Hanoi (air conditioning upgraded on the bus). Good boat and cabin, we ate well, fantastic happy hour on deck at sunset (great cocktails!!!). The bay is objectively beautiful and worth the experience, the trips are very fast maybe a little too much. You get about 15 km from the coast and then a taste of the bay. In general however all very well organized. It's worth it.