Things to do on the water in Koh Samui

The sea off Koh Samui is sold in eight different shapes, and a day on it runs from ฿2,300 ≈ $64 per person to ฿79,000 ≈ $2,188 for a whole yacht. A seat on a shared speedboat to Ang Thong or Koh Tao is ฿2,300. A day of sea kayaking in the marine park is ฿2,800. A snorkelling place on a dive boat is ฿2,900, a three-hour kitesurfing taster ฿7,000, a full day on a trophy fishing lake ฿7,000 and a four-hour jet ski safari ฿8,000 for the machine. Above that the unit changes from a person to a hull: ฿22,000 for a sunset sail, ฿25,900 for a half-day wooden Thai yacht and ฿79,000 for a full-day private charter. What follows is the map of that market — who leaves from where, when the Gulf season opens and closes, from what age children are taken and what to settle before you pay.

• The entry price in each of the eight categories, and the unit the operator prints it in
• Bangrak, Nathon, Maenam, Bophut, Hua Thanon and Taling Ngam: who leaves from where
• A season that runs opposite to Phuket — and the month the marine park closes
• Age thresholds: seven, ten, twelve and eighteen
• Park fees, deposits and cancellation: six questions before you pay

What is there to do on the water in Koh Samui, and what does a day cost?

Eight categories differ not only in price but in the unit the price is counted in, and the unit matters more than the figure. Speedboat days, kayaking, diving, kitesurfing and lake fishing are counted per person. A jet ski is counted per machine, with one or two riders on it. Sailing charters and the wooden Thai yachts are counted per hull, whatever the headcount inside the rate. So ฿2,300 and ฿25,900 in the table below are not neighbouring figures — they are money of a different kind.

Five of those eight lines rest on a single published price list — kayaking, kitesurfing, fishing, boat hire and jet skis each have one operator naming the figure. That is worth knowing before you treat the number as a market rate: in those five categories the Samui price is one company’s price, and there is nothing on the island’s published pages to compare it against. In the three remaining categories — boat days, diving and sailing — more than one price list exists, and the spread inside them is where the choosing happens.

The cheapest way onto the water starts at Bangrak pier. The Ang Thong Marine Park speedboat day costs ฿2,300 per person for eight hours, pickup at 08:30 and back at 16:30, with a light breakfast, a Thai buffet lunch, fruit, water, snorkelling gear, kayaks and passenger insurance inside the rate. The national park fee is not: the operator prints it as a separate table, ฿300 for a foreign adult and ฿150 for a foreign child, collected on the day.

The whole price ladder by category, with the arithmetic for a couple and for a family, is laid out in Koh Samui tours and excursions: what actually runs and what it costs. What a week of it adds up to for two is counted in A week on Koh Samui.

Two speedboat days from Bangrak: Ang Thong and Koh Tao

Both shared days leave the same pier, cost the same and differ in one line of the bill: the entry fee at the far end. Ang Thong is the archipelago day — the Emerald Lake on Koh Mae Ko, snorkelling at Koh Wao, kayaking under the limestone. Koh Tao is the snorkelling day — the viewpoint over the Koh Nang Yuan sandbar and three stops in the clearest water in the Gulf. The operator states a group of one to thirty-eight on both, which means neither has a minimum to meet.

The Koh Tao and Koh Nang Yuan day is the longer of the two at about eight and a half hours — pickup at 08:00, the boat out of Bangrak at 09:00, back on Samui at 16:30 — and it costs ฿2,300 per person. Setting foot on Koh Nang Yuan is charged separately by the island itself: ฿250 for an adult and ฿120 for a child, paid on arrival, against ฿300 for the Ang Thong park. That is the whole difference between the two bills.

Language is the other thing worth checking before you book. The operator runs the trips in English every day and puts a German-speaking guide on board on Mondays, Wednesdays and Fridays, which is narrower than “guides in English and German” sounds. Which of the two days suits which traveller, and what each one actually buys, is compared in Ang Thong from Koh Samui: speedboat or kayak and in Koh Tao day trip from Koh Samui.

Sea kayaking: one day, two paddling sessions and a park fee already inside

The kayak day is the one place on this list where the national park fee is not a line you pay on the boat. The Ang Thong sea kayak and snorkel day costs ฿2,800 per person with the marine park entrance listed among the inclusions, alongside the hotel transfer both ways, a light breakfast, a Thai lunch buffet, snorkelling gear, dry bags and insurance. The day runs 07:00 to about 18:00 door to door, on a 23-metre boat leaving Nathon pier at 08:00.

The rate falls as the group grows: the operator lists ฿2,700 per person from three people and ฿2,600 per person from five. Children have a bracket of their own, and it is the one place on the site where the operator argues with itself — the price page words it as ages 5 to 11 at ฿1,850, the cancellation page as ages 6 to 11. Under-fives travel free and the adult rate starts at twelve, but the operator also states that children of three and under are not permitted to kayak. If your child is five or six, that is a question for the booking message rather than for the pier.

Two paddling sessions in a day rather than one token outing is the operator’s own claim, and the first of them goes to Koh Tai Plao in the far north of the park — caves, tunnels and a hidden lagoon, where the company states it is normally the only boat. Cancellation is spelled out to the hour: more than 48 hours before departure, a full refund; less than 48, 25 per cent of the total; less than 24, the full charge.

Diving and snorkelling: three price lists, three levels

The cheapest way onto a Samui dive boat is not a dive at all. A snorkelling place on the dive boat of a Bophut centre is priced at ฿2,900 per participant on the operator’s own tour page, lunch included, with a free hotel transfer from Bophut, Chaweng, Bangrak and Choengmon and other areas on request. The boat may be heading for the Marine Park, Koh Tao or Sail Rock, depending on the day; you stay at the surface while the divers on board go down.

That figure needs an asterisk. The centre’s tour page states the price in words as 2,900 baht per participant, and its own shop page sells the same trip at ฿2,500 reduced from a struck-through ฿3,480. Three numbers, one tour, one website. Confirm which of them applies to your date before you pay.

To breathe underwater without a certificate, the try dive at Koh Tao is ฿5,900 per person: two supervised dives to a limited depth of twelve metres, no more than two students per instructor, with equipment, training material, lunch and the hotel transfer inside the rate. Pickup is at 08:00, the speedboat crosses between 09:00 and 10:30, and you are back at the hotel by 16:00.

Certified divers pay less, because they need supervision rather than instruction: the same centre prices its two-dive Koh Tao day at ฿5,000 per person and its Sail Rock day at ฿4,700. The pinnacle itself has its own boat. Two dives on Sail Rock cost ฿4,650 per person for a day of about eight hours, with hotel transfer, all rental equipment, diving insurance, free Nitrox for Enriched Air divers and lunch on board. Whale sharks are around much of the year, the operator says, with peak months in March to May and August to October, and it does not promise them.

The Sail Rock boat runs on Tuesdays, Wednesdays, Fridays and Sundays and asks for a booking at least 24 hours ahead, which is the tightest schedule in this guide. It is also the only trip here that is closed to beginners: a valid Open Water certificate or the equivalent is required. What each level actually buys, site by site, is set out in Diving and snorkelling from Koh Samui.

Private boats: half a day, a sunset and a whole day

Boats you hire whole are counted per hull, and that is where a group changes the arithmetic completely. The entry point is the classic wooden Thai yacht: a half-day charter to Pig Island costs ฿25,900 for the boat with the first six people inside the rate, and each further adult is ฿1,200, each child ฿800. Departures are 09:30 to about 14:15 and 14:15 to 19:00, round-trip transfers from anywhere on the island are part of the charter, and the Pig Island admission fee is already in it.

A bigger group changes hull rather than paying per head: the operator’s Red Dragon costs ฿43,000 for the same half day, carries ten people inside the rate and takes up to 74 aboard, with the same ฿1,200 and ฿800 for extras. Sea kayaking in the Koh Taen mangroves is the one optional line, ฿200 per person; guided snorkelling on the reef is already in the rate.

Under sail the entry point is the evening. A private sunset sail on a 52ft yacht costs ฿22,000 for the charter with two guests already included, each further guest ฿2,500 and up to six aboard on this trip. Pickup anywhere on Samui is at 16:00–16:30, the boat casts off at 17:00 and is back by 19:30, and the rate carries a skipper, a hostess, an open bar of beer and wine, sunset tapas and a bottle of champagne. The same yacht sells longer days: ฿27,000 for a five-hour Koh Phangan half day, ฿38,000 for eight hours and ฿45,000 for eleven hours out to Ang Thong.

The top of the range is a whole yacht for a whole day. A full-day private charter out of Petcherat Pier is ฿79,000 for the boat, covering up to twenty people, with a full breakfast, lunch, snacks, fruit, all drinks, towels, accident insurance and an English- and German-speaking guide. The operator prices the Ang Thong itinerary higher, from ฿89,000, and states a maximum of fifty on board for the day charter. Its price block says eight hours and its inclusions say eight to ten — worth pinning down when you agree the route.

Jet skis, kitesurfing and fishing: where the choice is thin

These three categories have a page of their own on Samui and one published price list behind each, which changes how you should read the number: it is a quotation, not a range. The four-hour jet ski safari costs ฿8,000 for the machine with up to two riders, running from Maenam Beach across to Koh Phangan with three beach stops on the way, snorkel masks, drinking water and accident insurance included. The same operator sells a three-hour version of the same route at ฿6,500, and lists neither lunch nor transfers.

The age rules on that page are stricter than they look. The operator writes the minimum driver’s age as eighteen and says that anyone under eighteen rides accompanied by an adult, while describing the ride as suitable for travellers with children from seven years old. Two numbers, one page: eighteen to hold the handlebars, seven to sit behind.

Kitesurfing sits on the south-east coast at Hua Thanon. The Discovery Session costs ฿7,000 for three hours: beach theory and the safety systems, then kite control, then practice in the water, with a private instructor, all equipment and insurance for that equipment. What the school does not say anywhere on that page is whether the figure is per person — so if you are two, ask, because the same school prices its semi-private lessons explicitly per person, at ฿1,900 an hour for two people sharing one instructor and one kite. Courses carry on at ฿13,000 for six hours, ฿19,000 for nine and ฿24,000 for twelve.

Fishing on Samui is the odd one out: it is freshwater, and it is not a boat. The full day on the specimen lake at Taling Ngam costs ฿7,000 per person fishing — the price page states the unit in those words — for twelve hours from 08:00 to 20:00, with two rod set-ups, a full daily bait pack, shaded salas with power and a guide who nets and unhooks for you. Shorter sessions are ฿4,500 for the predator half day and ฿3,800 for the early bird; four hours are by arrangement only, and arapaima is a session of its own rather than a fish you add on.

Why the island’s fishing is a lake rather than a charter, and what that means for someone who came for trolling, is explained in Fishing on Koh Samui: a trophy lake, not a sea charter.

Where the boats leave from: Bangrak, Nathon, Maenam and the south

Samui’s departures are spread right around the ring road, and the pier decides your morning more than the hotel does. Bangrak, on the north-east corner, is the busiest: the speedboat operator runs its own pier there at Bangrak Beach and measures the island from it — about ten minutes from Chaweng, eleven from Bophut and the airport and thirty-three from Lamai. Boutique Yachting leaves from Petcherat Pier in the same Bangrak, with pickups staggered from 07:50 in the far south through to 09:00 in Bangrak itself.

Nathon, on the west coast, is the ferry town and the kayak departure: the 23-metre tour boat leaves Nathon pier at 08:00, and guests coming over from Koh Phangan are told to take the 07:15 catamaran that lands at Nathon at 07:45, right next to it. Maenam, on the north coast, is where the jet ski safari starts before crossing to Koh Phangan. Bophut and Fishermans Village hold two dive centres and the base of the sailing yacht; the centre addresses are on Moo 1 in Bophut, and the sunset van collects from anywhere on the island.

The south and the south-west are where the two land-based bases sit. The kitesurfing spot is at Hua Thanon in Maret on the south-east coast, open 09:00 to 18:00 daily, and the school does not state that it provides a transfer. The fishing resort is at Taling Ngam in the south-west, open 08:00 to 20:00. And Lamai, the island’s second big beach, is the honest gap in this map: nothing on these operators’ pages departs from Lamai — it appears only as a distance, thirty-three minutes to the pier at Bangrak.

Which coast to stay on, and how the answer changes with the month, is worked through in Koh Samui beaches: which coast to choose and when. How you get to the island in the first place is in Koh Samui ferry and flights.

The season runs the other way round to Phuket

This is the single most useful thing to know about Samui, and the one most often got wrong. The island sits inside the Gulf of Thailand, sheltered by the Tenasserim range from the south-west monsoon that soaks the Andaman coast from May to October. The kayak operator publishes a climate page built on thirty-year normals from the Thai Meteorological Department’s Ko Samui station, and the contrast it prints is blunt: in July and August Samui gets 110 to 130 mm of rain against 280 to 310 mm on the Phuket and Krabi side. In September it is about 190 mm here against 380 to 420 mm there.

The dry season here runs from December to February or March, with 28 to 31 °C by day, water at 27 to 28 °C and the operator describing the bays as mirror-flat with visibility to twenty-five metres. February is statistically the driest month of the year, 44 mm across two rain days. The hot season stretches March to August; April is the hottest, and May has the warmest water of the year at 30.5 °C. The green season is September to November, and November is the wall: 495 mm across eighteen rain days, against 312 mm and sixteen days in October.

That November wall is why the marine park closes, and why the two published closure windows matter. The kayak operator states the park resting from 1 to 30 November and its own Ang Thong kayak day resuming on 1 December, and it also publishes a safety routine of its own: at 06:00 every morning the captains review radar, wave models and advisories before the boat leaves Nathon, and if the conditions fall short, the day is moved free of charge or refunded in full. The speedboat days out of Bangrak are described with a longer window, closed from 1 November to 15 December.

Diving keeps its own calendar on top of that. The Sail Rock operator says whale sharks are present through much of the year, with peak months in March to May and August to October — so the best underwater month and the best beach month are not the same month. The month-by-month picture of rain, wind and water is laid out in Koh Samui best time to visit, and the wider question of which sea Samui sits in is answered in Koh Samui island: where it is and when to go.

With children and as a beginner: the published age thresholds

The thresholds on Samui do not line up, and the gaps between them are wide. Diving starts at ten, the adult kayak rate at twelve, a jet ski passenger at seven and a jet ski driver at eighteen. On the shared speedboats age changes the fare rather than the admission.

The gentlest first step underwater is the try dive at ฿5,900 per person: no certificate, no experience, a maximum of two students per instructor and a ceiling of twelve metres. It is not a certification in itself, but the centre offers a free SSI Basic Diver upgrade on request, and if you start the Open Water course within six months your first open water dive counts towards it. A non-diving companion can come on the same boat and snorkel.

Which trip works at which age, and what the family arithmetic looks like once the park fees are added, is worked through in Koh Samui with kids. If the days need stitching into an itinerary, Koh Samui in four days puts them in an order that fits.

Six questions to settle before you pay

First, the park fee, because Samui has both kinds. The kayak day puts the marine park entrance inside the rate and collects nothing on the day. The Ang Thong speedboat day leaves it outside, ฿300 for a foreign adult and ฿150 for a child, and the Koh Tao day leaves the island fee outside too, ฿250 and ฿120. The operator prints a separate column for Thai residents at ฿40 and ฿20 — a good sign that the table you are reading is the real one.

Second, the unit, because not every category here is counted per person. Third, what is actually inside. The snorkelling place on the dive boat at ฿2,900 has lunch inside and a free transfer from four named areas only; the jet ski page lists neither lunch nor transfers; the kitesurfing school does not say it provides a transfer to its spot at all. On the wooden yacht the admission to Pig Island is inside the charter and the kayaking is not.

Fourth, cancellation, and here the island is uneven. The kayak operator spells it out to the hour — full refund beyond 48 hours, 25 per cent inside 48, the full charge inside 24 — and promises a free move or a full refund when it cancels for weather itself. The dive boat to Sail Rock asks for 24 hours’ notice simply to hold your place. Most of the other pages say nothing at all about cancellation, and silence on a page is not a policy.

Fifth, the flight home: no operator here lets you dive and fly on the same day, and both dive centres repeat the eighteen-hour rule. Sixth, the extra guest. On the wooden yacht each adult beyond six is ฿1,200 and each child ฿800; on the sailing yacht each guest beyond two is ฿2,500; on the jet ski the second rider costs nothing at all, because the machine is the unit. Work out which of the three you are buying before you divide the price by the number of people.