Island days with a family: Phi Phi, Hong, Similan and the rest.

What a day trip actually involves

The standard island day is longer and more physical than families expect. A shared tour collects you between seven thirty and eight thirty, delivers you to a pier, boards a speedboat carrying anywhere from twenty to sixty passengers, and runs at speed to two or three stops with an hour at each, a buffet lunch on a beach, and a return in the middle of the afternoon. Boarding is usually a wade from the sand or a step across a moving gunwale. There is little shade, one small toilet, and no privacy of any kind. For a young couple it can be a fine day. For a grandmother, a pregnant daughter, three children under seven and a household of fourteen, it is the wrong instrument entirely.

The alternative is to take the boat rather than a seat on it. A private speedboat or a small motor cruiser for the day changes every variable at once: your departure time, your route, your stops, who is aboard, what is served, when you pray, and how quickly you come home if a child has had enough. On the Andaman coast this is an established and competitive market, priced by boat size and hours rather than by head, and for a family of ten or more the cost per person frequently lands close to what the shared tour would have charged. We book it as a default for any party above six, and for any party including elderly passengers or small children regardless of size.

Private against shared

The islands worth a day

Phi Phi is the famous one: two main islands south of Krabi, limestone walls dropping straight into clear water, and the most photographed bays in Thailand. It is also the busiest, and the difference between arriving at nine and arriving at seven is the difference between a queue of boats and an empty bay. Maya Bay, on Phi Phi Leh, is managed by the national parks department and has been subject to seasonal closures and to restrictions on how boats may approach and where people may swim, so its status must be checked for your dates rather than assumed. From Phuket the crossing is roughly forty five minutes by fast boat, from Ao Nang somewhat less.

The Hong islands, in the eastern part of Phang Nga Bay off Krabi, are the gentler option and often the better one with children: a group of limestone islands with a famous enclosed lagoon, shallow water, short crossings and calmer conditions than the open runs to Phi Phi. Phang Nga Bay itself, north of Phuket, is a landscape rather than a beach day: hundreds of limestone stacks in shallow protected water, sea caves, and the stack made famous by a film in the nineteen seventies that every boatman will offer to show you. Because the bay is enclosed, it is the most reliable choice in unsettled weather and the kindest to anyone prone to seasickness.

The Similan and Surin islands, out in open water northwest of Khao Lak, are the finest snorkelling and diving in the region and the most demanding trip: a long fast run offshore from the Phang Nga coast, and a national park that closes for the monsoon each year, typically from around mid May to mid October. Those dates are set by the parks department and can shift, so confirm before planning. Closer to home, Racha Yai and Coral Island south of Phuket make short easy half days, and Koh Yao Noi and Koh Yao Yai in the middle of the bay are quiet inhabited islands with beaches, villages and mosques rather than tour crowds.

Timing the day

Two rules cover most of it. Go early, and go against the fleet. The commercial boats leave the main piers between eight thirty and nine thirty and arrive at the headline stops in a mass; a private boat leaving at seven has an hour and a half of clear water and can then move to a second island as the crowd arrives at the first. In the afternoon the wind on the Andaman usually freshens from late morning onward, so the sea is at its flattest early and the return leg after three can be uncomfortable. Our standard shape for a family day is a seven o'clock departure, two stops before eleven, lunch aboard at anchor in a sheltered bay, a swim and a rest through the middle of the day, and back alongside by three.

Seasickness, children and the practical kit

Seasickness is the commonest reason a family day fails, and it is mostly a matter of boat choice and route. Speedboats slam; larger displacement boats and catamarans ride far better; enclosed bays are calmer than open crossings. Anyone susceptible should be seated low and near the centre of the boat, facing forward, with the horizon in view, and should not be reading or looking at a phone. Any medication for motion sickness is a matter for the family's own doctor or pharmacist, not for us, and should be sorted before travel rather than at a pier. Bring far more water than seems necessary, hats and long sleeves rather than relying on sunscreen alone, and a dry bag for phones and documents.

• Children need properly fitted life jackets sized for their weight, not adult jackets. Confirm the boat carries child sizes when booking, and count them aboard.
• Boarding is the riskiest few seconds of the day. Ask for a pier departure rather than a beach wade when travelling with elderly passengers or a wheelchair.
• Shade on a speedboat is minimal. For a full day with small children, take a larger boat with a saloon.
• Reef shoes matter: coral, urchins and rock are common at the waterline on island beaches.
• Take cash for national park entry fees, which are collected per person at the islands and are higher for foreign visitors.

Prayer, food and modesty at sea

On a private boat this is straightforward and crews on the Andaman coast handle it as a matter of routine, in large part because many of them are Muslim themselves. Tell the skipper at booking that prayer times will be observed, and the boat can be stopped and held head to wind at anchor for the duration, which gives a stable platform and a clear direction. Ask for a clean covered area, usually the saloon or the foredeck under an awning, and bring your own mats. Determining the qibla is simple with a phone compass, and the crew will tell you the heading if asked. Fresh water aboard is limited, so plan ablution around the tanks and carry extra bottled water for it.

Food is easier still: provision the boat yourself or have your villa kitchen prepare the day's meals, which sidesteps the certification question altogether. If the charter is catering, put the dietary standard in writing and be specific, because a Thai galley that has never been asked will not guess. For modesty, a private boat is the only real answer at sea: shared boats have one changing space at best, whereas your own boat can be arranged so that women swim from the stern with the crew forward, or with a section of deck screened. Modest swimwear is entirely unremarkable in southern Thailand, and no crew will find the request unusual.

Fees, closures and the weather call

Most of the islands worth visiting sit inside marine national parks, which means an entry fee per person collected on arrival, higher for foreign visitors than for Thais, and rules about anchoring, feeding fish and touching coral that responsible operators enforce. Several parks close entirely for part of the year. Beyond the parks, the harbour authorities can and do suspend departures when conditions are poor, and a reputable operator will cancel rather than sail. Take that seriously. If your skipper says the crossing to Phi Phi is not on today, the correct response is to take Phang Nga Bay instead, not to find another boat that will go.

Confirm marine national park opening dates, entry fees and any bay restrictions with the Department of National Parks, Wildlife and Plant Conservation before booking a trip, verify that your charter operator is licensed and insured with the Marine Department of Thailand, and check daily sea state and small craft warnings with the Thai Meteorological Department at tmd.go.th.

This briefing is general information, not legal, tax or investment advice. Thai rules change frequently and individual cases differ. Verify current requirements with the relevant authorities, including the Immigration Bureau, the Board of Investment, the Land Department, the Department of Business Development and the Revenue Department, and take advice on your own facts before acting.