Life on board

A crewed catamaran under about eighteen metres carries two: a captain who runs the yacht and a chef or hostess who does everything else. From about twenty-four metres a stewardess and a deckhand appear, and above thirty metres an engineer and a second stewardess. The captain is responsible for the yacht, the itinerary and your safety, and has final say on where the yacht goes; the chef cooks to your preference sheet; the stewardess runs the interior and the service; the deckhand runs the tender and the water toys.

The preference sheet is the form sent about a month before a crewed charter that tells the chef and the captain what to buy and how to run the week: food and drink preferences, allergies and dietary requirements, dive certifications, celebrations, how early you want to start, how much you want to move each day. It is provisioned against before you arrive. Allergies and dietary requirements are the two sections that cannot be corrected later, because a yacht at Koh Rok is fifty miles from a supermarket.

Every crewed yacht carries a tender, snorkelling equipment and paddleboards, and those three get used every day. Kayaks earn their place in the Andaman more than anywhere else, because the cave and lagoon entrances at Koh Panak and Koh Hong can only be reached by paddle. Seabobs are genuinely fun and heavily used. Jet skis are restricted in the national parks and used less than people expect. E-foils need flat water, an hour of instruction and a patient crew, and are the toy most likely to stay in the locker.

There are three arrangements. A yacht with its own compressor, tanks and a dive-qualified crew member lets you dive straight off the transom, which is the best of them and the rarest. A yacht that rendezvouses with a local dive operation gets you guided dives without carrying the equipment. And a yacht that simply anchors near a dive centre leaves you booking day trips, which wastes the advantage of being on a yacht at all. Which one you have is worth establishing at enquiry, because it changes the itinerary rather than just the packing.

Phang Nga Bay suits young children unusually well: the water is flat, no passage is longer than about three hours, and the caves, lagoons and kayaks are more interesting to a seven-year-old than any beach. What does not suit them is a short charter that tries to reach Phi Phi or the Similans, where most of two days is spent under way. Ask about netting on a catamaran, child-sized buoyancy aids, whether the crew have worked with young children before, and whether cabin air conditioning runs all night.

Phuket provisions well and a competent charter chef handles vegan, vegetarian, halal, gluten-free and most allergies without difficulty, provided it is on the preference sheet about a month before departure. Kosher provisioning needs more notice and is usually arranged through a supplier in Bangkok. Severe allergies need to be stated with the person's name and the severity, because a yacht at Koh Rok is fifty nautical miles and several hours from a pharmacy, let alone a hospital.