Short answer
Bring a dry bag, water shoes, sturdy walking shoes, sun protection and a light rain jacket all year. Add a fleece and long trousers from December to March, and strong insect repellent in summer.
01All year
- Dry bag (10–20 litres). For phone, wallet and camera on kayaks and boats.
- Water shoes or sturdy sandals. Beaches in the bay are often rocky and studded with oyster shells.
- Walking shoes with grip. The national park trails are rocky, steep and slippery after rain. Flip-flops will not do.
- Sun protection. Hat, sunglasses, high-factor sunscreen and a light long-sleeved shirt for long days on the water.
- Light rain jacket. Rain can come in any month, and it doubles as a windbreaker on boats.
- Head torch. Useful in caves, on early hikes and during power cuts.
- Refillable bottle and a small first aid kit with plasters, rehydration salts and motion sickness tablets.
- Power bank and adapter. Sockets take flat and round two-pin plugs.
02May to September extras
- Quick-dry clothes and a spare set: the humidity means nothing dries overnight
- Strong insect repellent and after-bite cream
- Rash vest or swim shirt for long snorkelling and kayaking sessions
- A waterproof phone pouch for sudden downpours
03December to March extras
- A fleece or light down jacket for evenings and boat decks, when it can feel close to 12–15 °C with the wind
- Long trousers and closed shoes
- A warm layer for sleeping in older guesthouses, which often have no heating
04Leave at home
- Large hard-shell suitcases: you will drag them over gangways, steps and sand
- Expensive jewellery
- Drones, unless you have checked the current rules; flying over military areas and some protected zones is banned
?Questions people ask
Do I need hiking boots for Cat Ba?
Not heavy boots, but proper trail shoes or trainers with good grip. The trails to Ngu Lam Peak and Viet Hai are rocky and slippery when wet.
Can I buy what I forget on Cat Ba?
Basics yes: sunscreen, hats, flip-flops, dry bags, raincoats and toiletries are sold in town. Specialist gear, good sunscreen brands and medicines are better bought in Hanoi.