Island hopping from Trang.

Trang's headline attraction: an 80-metre dark limestone tunnel that opens into a hidden lagoon ringed by sheer cliffs and jungle, its sunlit water taking on an emerald glow around mid-morning. Reaching it means swimming or being towed through the pitch-black passage from a longtail boat, so tours only run it inside a specific low-tide window (roughly 10:30-11:30am) when the tunnel is passable - outside that window the cave is inaccessible. Koh Mook itself also has a relaxed village, a pier-side seafood scene and Farang Beach (Hat Farang) for a swim after the cave.

A slender, largely undeveloped island inside Hat Chao Mai National Park, ringed by some of the powdery-white, calm-water beach in the Trang chain and a fringing reef just offshore that makes for easy snorkelling straight from the sand. Nicknamed the 'Island of Love' by some tour operators, it's usually paired with Koh Mook and Koh Cheuak on the same day-tour circuit rather than visited alone.

Trang's most upscale island, ringed by a long white beach and clear water, and popular with couples and honeymooners. There's no village or ATM - just a handful of resorts - so most visitors come to stay rather than just day-trip. Reachable by longtail boat from Pak Meng Pier (about 50-60 minutes) or by speedboat ferry from Koh Lanta to the north (about 40 minutes), making it a genuine link between the Trang and Krabi island chains.

A small, uninhabited islet with a narrow sandbar and healthy coral just offshore, almost always visited as a snorkelling stop bolted onto a Koh Mook/Koh Kradan day tour rather than a standalone destination - a quieter, less crowded add-on between the two bigger islands.

Trang province's largest island, and a very different kind of island trip - its extensive seagrass meadows are the country's biggest dugong habitat, home to roughly 200 of Thailand's remaining wild dugongs (around 70% of the national population). Boat trips head out to the seagrass flats for a chance to spot them from a respectful distance, and the Dugong Watching Tower near Laem Chao Mai/the Leekpai Bridge gives an elevated shore-based view. Also good for birdwatching and quiet, low-key village guesthouses. Reached via public ferry from Hat Yao Pier (about 30-45 minutes), separate from the Pak Meng day-tour piers.

A rarely-visited island further south, reached from Baan Ta-Seh Pier or the newer Saphan Mai Pier near Palian (about a 20-minute longtail crossing). Known for its Muslim fishing community, watermelon farms, halal seafood and simple homestays rather than resorts or organised tours - a genuine off-the-beaten-path option for travellers basing in southern Trang.

The default way to cover the Emerald Cave, Koh Kradan and Koh Cheuak in one day from Pak Meng - faster than a longtail, run in shared groups of roughly 15-30 with lunch, snorkel gear and hotel pickup usually included.

Thailand's classic wooden boat is the standard scheduled option from Pak Meng Pier to Koh Ngai (two departures a day) and a common choice for private inter-island transfers - slower than a speedboat but cheaper, and closer to the water.

Koh Libong and Koh Sukorn are everyday commuter islands, not resort day-trip destinations, so they're served by inexpensive public ferries from Hat Yao Pier and Baan Ta-Seh/Saphan Mai Pier rather than tour-operator speedboats - book on arrival at the pier, not online.

A private longtail or speedboat for a half or full day lets you set your own route - useful for reaching Koh Ngai or Koh Sukorn on your own schedule, or combining the Emerald Cave with a quieter, less crowded island stop. Priced per boat, so it's cost-effective split across a group of 6-10.

A shared speedboat day tour covering the Emerald Cave, Koh Kradan and Koh Cheuak from Pak Meng typically runs about 1,200-1,800 THB per person, usually including snorkel gear, a buffet lunch, hotel pickup in Trang town and national park fees.

Foreign adults pay 200 THB plus a 50 THB Dugong Fund conservation surcharge (250 THB total), with an extra 30 THB if a vehicle is involved - this covers the park's islands including Koh Kradan and the Emerald Cave area on Koh Mook, and is sometimes bundled into the tour price rather than collected separately, so confirm when booking.

The scheduled longtail runs about 400 THB for adults and 250 THB for children one-way, with two daily departures; some resorts arrange a return transfer from Koh Ngai back to Pak Meng from around 475 THB.

For travellers coming from or continuing to Krabi's Koh Lanta, the ferry link to Koh Ngai runs roughly 650 THB for adults and 450 THB for children, operated by Satun Pakbara Speed Boat Club.

A private longtail from Pak Meng Pier to the islands generally runs about 800-1,500 THB per boat depending on distance and destination - split across a small group, this can undercut the per-person tour price.

These are everyday local ferries rather than tourist tours, so fares are modest compared with the day-tour boats - pay at the pier rather than booking online, and expect a simpler, no-frills crossing.

November to April is the Andaman dry season - calm seas, clear visibility and the reliable window for day tours. Trang's wet season runs longer and heavier than nearby Krabi's: from roughly May to October many ferry services thin out or suspend, and some smaller-island resorts close entirely, so shoulder-month travel needs extra confirmation with operators.

Pak Meng Pier, about 40 minutes from Trang town, is the main hub for day tours to the Emerald Cave, Koh Kradan, Koh Cheuak and the scheduled Koh Ngai longtail. Hat Yao Pier handles the separate public ferry to Koh Libong. Baan Ta-Seh Pier and the newer Saphan Mai Pier, near Palian in the south, serve Koh Sukorn. Confirm your pier when booking - hotel transfer times vary a lot depending on which one you need.

The cave's 80-metre swim-through tunnel is only passable inside a specific low-tide window, commonly cited as around 10:30-11:30am, and the best emerald light inside the lagoon is generally between about 10am and 2pm. Tour operators build their schedule around this, so an independent visit needs the day's tide table checked in advance - going at the wrong tide means the tunnel simply isn't swimmable.

Book through a Trang town hotel tour desk, an agent at Pak Meng Pier, or online platforms (Klook, GetYourGuide, Viator and similar) that let you compare operators and lock in a fixed price with hotel pickup. Koh Libong and Koh Sukorn ferries are the exception - buy those tickets at the pier, not online.

Reef-safe sunscreen, a rash guard for the Emerald Cave swim, water shoes (the tunnel floor and some landing points are rocky), a dry bag for phones and cash, and a headlamp or waterproof torch if your tour doesn't supply one for the cave passage. Cash in small denominations covers park fees and pier-side extras.

The Emerald Cave (Tham Morakot) on Koh Mook is an 80-metre dark limestone tunnel that opens into a hidden, cliff-ringed lagoon. You swim or are towed through by longtail boat, and it's only accessible inside a specific low-tide window (roughly 10:30-11:30am) - outside that window the tunnel isn't passable, so tours are timed around the day's tides.

A shared speedboat day tour to the Emerald Cave, Koh Kradan and Koh Cheuak typically runs about 1,200-1,800 THB per person including lunch and snorkel gear. The Hat Chao Mai National Park entrance fee (250 THB for foreign adults, including the Dugong Fund surcharge) is sometimes charged separately. Reaching Koh Ngai by scheduled longtail from Pak Meng costs around 400 THB one-way.

Koh Libong's seagrass meadows are Thailand's largest dugong habitat, home to an estimated 200 dugongs - about 70% of the country's population. Boat trips go out to the seagrass flats for a chance to spot them from a respectful distance (a 5-metre minimum approach rule applies), and the shore-based Dugong Watching Tower near the Leekpai Bridge is a lower-effort alternative. Sightings are never guaranteed, since these are wild animals in open water.

No. November to April is the reliable dry season with calm seas. From roughly May to October, Trang's wet season is longer and heavier than nearby Krabi's - many ferries thin out or suspend and some smaller-island resorts close, so travel in the shoulder months should be confirmed directly with operators before booking.

Trang's islands - Koh Mook, Koh Kradan, Koh Ngai, Koh Cheuak, Koh Libong and Koh Sukorn - are considerably less developed and see far fewer visitors than Phuket or Krabi's Four Islands and Phi Phi routes. There's no equivalent to Patong or Ao Nang's tourist strip; most islands have a village, a handful of resorts, or nothing at all. That trades convenience and departure frequency for quieter beaches and a genuine swim-through cave you won't find on the busier circuits.

Pak Meng Pier (about 40 minutes from Trang town) covers the Emerald Cave, Koh Kradan, Koh Cheuak day tours and the scheduled Koh Ngai longtail. Hat Yao Pier is the separate departure point for the Koh Libong public ferry. Koh Sukorn is reached from Baan Ta-Seh Pier or Saphan Mai Pier near Palian in the south - always confirm which pier your tour or ferry uses when booking.