1. Lan Ha Bay Cruise, April 2018. As beautiful as Cat Ba Island is, for most visitors the main reason to come out here is for a boat cruise through the region’s spectacular Lan Ha & Halong bays. Choose your tour operator VERY CAREFULLY, as the scene is riddled with tricksters and scammers. Some have shoddy boats not fit for purpose, others blatantly lie to you about the itinerary, either rushing you through key points of interest or even skipping the highlights completely. After much research I opted for a cruise with the highly rated Green Trail, who have an office on the main drag in Cat Ba Town.