When to visit Lan Ha Bay and Cat Ba Island: weather, sea temperature and crowds month by month, the best season for swimming and glowing plankton, winter mist and holidays to avoid.

Kayaking hidden lagoons, hiking Ngu Lam Peak, glowing plankton, floating houses, Viet Hai village and fresh seafood – the 10 best things to do on Cat Ba Island, with practical tips from our local team.

Lan Ha Bay or Ha Long Bay? A local comparison of crowds, kayaking, beaches, starting points, travel time and prices – plus how to see both bays in one trip.

Every way to travel from Hanoi to Cat Ba Island – bus and speedboat from US$11, cable car, luxury cruise via Ha Long Bay, airport transfers and private cars – with real schedules, prices and tips from our local team.