Koh Samui Island Hopping Day Trips: Ang Thong, Koh Tao and Koh Nang Yuan

Koh Samui’s position in the Gulf of Thailand places it within striking distance of some of the region’s most photogenic islands. A single day’s boat trip from Na Thon pier or Mae Nam beach can deliver limestone sea stacks, emerald lagoons and coral gardens that rival anything in southern Thailand. Three destinations pull the most demand from day-trippers: Ang Thong Marine Park’s cluster of 42 uninhabited islands, Koh Tao’s world-class dive sites, and Koh Nang Yuan - a trio of tiny islets linked by a white sand bar.

Ang Thong Marine Park Day Trip

The Mu Ko Ang Thong National Marine Park lies 31 kilometres northwest of Koh Samui and covers 102 square kilometres of Gulf of Thailand waters. Access is restricted to licensed tour operators - you cannot arrive independently by private boat without prior arrangement.

What to Expect

Most tours stop at two or three islands within the park. Ko Mae Ko is the most-visited, offering a 2-kilometre hike to a saltwater inland lake (Talay Nai) ringed by limestone cliffs - the lake that reportedly inspired Alex Garland’s novel The Beach. Ko Sam Sao has the best snorkelling in the park, with hard coral gardens hosting sea turtles and reef fish in 3 to 8 metres of water. Ko Wua Talap, the park’s administrative island, has a viewpoint trail with views across the whole archipelago.

Tour Operators and Prices

Several established operators run this route from Koh Samui:

Mr Samui Tour (based at Mae Nam) runs a catamaran with a maximum of 60 passengers. Departures at 08:00, returns approximately 17:30. Price approximately THB 2,200 per person including national park fee (THB 300 for foreigners), lunch, snorkelling equipment and kayak hire at Ko Mae Ko.

Blue Stars Kayaking specialises in sea kayaking within the park for smaller groups (maximum 12). Full-day kayaking tours from approximately THB 3,500 including park fee, guide, equipment and lunch. This operator is well-regarded for low-impact exploration of the park’s sea caves.

Antares Sailing offers catamaran day tours with more relaxed scheduling - useful for anyone who finds speedboats uncomfortable. Prices from approximately THB 2,500 including snorkelling and lunch.

Ang Thong tours book out quickly between December and April - secure tickets at least 2 to 3 days ahead. Note that the park can close without warning during bad weather; reputable operators will arrange refunds or reschedule.

Koh Tao and Koh Nang Yuan Day Trip

Koh Tao sits 47 kilometres north of Koh Samui, making it a 1.5-hour speedboat journey each way. The island is Thailand’s top scuba diving destination, but its snorkelling - particularly around Koh Nang Yuan and Shark Bay on the island’s south side - is excellent for non-divers.

Koh Nang Yuan

Koh Nang Yuan is a trio of small islands connected by twin sandbars that create a perfect hourglass shape viewable from the island’s viewpoint. The sandbar is one of the most-photographed beaches in the Gulf of Thailand. Entry costs approximately THB 100 per person (paid on arrival), and the island bans plastic bags and glass bottles to protect its reefs. Snorkelling off the pier reveals hard coral in very shallow water.

Shark Bay (Haad Tien)

Despite the name, the sharks here are harmless blacktip reef sharks that congregate in the bay’s shallow sandy margins, particularly in the early morning. Snorkelling day trippers are regularly dropped off here for 45 minutes before continuing to Koh Nang Yuan or Freedom Beach. Water clarity is typically exceptional.

Tour Operators and Prices

Lomprayah is the main high-speed catamaran operator between Koh Samui, Koh Phangan and Koh Tao and offers the cheapest transport option at approximately THB 700 to THB 900 each way. This is a ferry rather than a guided tour - you manage your own time on Koh Tao.

For a guided snorkelling day trip that includes Koh Nang Yuan and Shark Bay:

Big Blue Resort (Koh Tao) runs snorkelling day charters from THB 1,800 to THB 2,200 per person including equipment, guide and lunch at their resort. Transfers from Koh Samui can be added.

Samui Ocean Sports offers speedboat day trips from Koh Samui to Koh Tao/Koh Nang Yuan from approximately THB 2,800 to THB 3,000 including snorkelling equipment, lunch on Koh Tao and the Koh Nang Yuan island fee.

Koh Madsum and Koh Tan (Near Koh Samui)

For those who prefer a shorter, quieter day trip without the longer speedboat crossing, Koh Madsum and Koh Tan lie less than 30 minutes south of Koh Samui.

Koh Madsum is a tiny beach island with a small pig population - the local farmers’ animals swim in the shallows and have become an accidental attraction. Long-tail boat day trips from Ban Hua Thanon or the southern piers cost approximately THB 800 to THB 1,200 including lunch on the island.

Koh Tan is larger, home to a few families and a handful of beach restaurants. It is the most relaxed of the island-hopping options - no crowds, no queues, and excellent snorkelling off its north beach. Combined Koh Madsum and Koh Tan day trips run approximately THB 1,000 to THB 1,500 per person including a beach lunch.

What to Pack

• Reef-safe sunscreen (SPF 30 minimum) - most parks ban chemical sunscreens
• A rashguard or light long-sleeve top for snorkelling; UV exposure on Gulf waters is intense
• Motion sickness tablets if prone to seasickness - the crossing to Ang Thong can be choppy
• Cash in THB for national park entry fees and optional food on islands (card payments are unavailable on most outer islands)
• A dry bag for phones and valuables on speedboats

Best Season for Island Hopping

The Gulf of Thailand follows a different weather pattern from Thailand’s Andaman coast. The clearest, calmest period for island hopping from Koh Samui is January to April, when northeast monsoon winds have passed and seas are flat. Visibility for snorkelling peaks in February and March.

May to September is generally fine on the Gulf side - drier than people expect - though scattered afternoon showers are common. Most tours run year-round during this period.

October to December is the Gulf’s wet season. Koh Samui receives heavy rainfall and the sea state becomes unpredictable. Ang Thong Marine Park suspends all tours when swell exceeds 1.5 metres, which is common in November. Koh Tao and Koh Nang Yuan tours on the park’s more sheltered western side operate more consistently. Always confirm departure the day before.

Booking Tips

• Book direct with operators rather than through resort front desks, which add 10 to 20 percent commission
• Group sizes matter - smaller speedboats (8 to 12 passengers) stop longer at each site than 40-person catamarans
• Check whether national park fees are included in the quoted price - Ang Thong’s THB 300 fee is sometimes quoted separately
• Cancellation policies vary: most operators offer a full refund if the park closes for weather, but weather-independent cancellations within 24 hours may forfeit 50 percent