Dive Site: HTMS Chang Wreck

About HTMS Chang Wreck

The HTMS Chang Wreck, an impressive artificial reef, is Thailand's largest purpose-sunk vessel, resting off the coast of Koh Chang in the Gulf of Thailand. This 100-meter-long ship, originally the USS Lincoln County, served in WWII and the Korean War before joining the Royal Thai Navy. In 2012, it was intentionally scuttled upright on a sandy bottom, transforming into a vibrant underwater metropolis at depths reaching 34 meters. Today, the wreck's decks, cargo holds, and passageways are extensively colonized by soft corals, sponges, and anemones, creating a stunning contrast against its steel structure. The site provides a thriving habitat for a diverse array of marine life, from small nudibranchs to large schools of barracuda and snappers. Accessible to advanced open water divers, the HTMS Chang offers both recreational wreck exploration and significant opportunities for technical wreck penetration for appropriately trained and certified divers. Its scale and structural complexity make it a prime location for advanced wreck and technical diving courses. The experience of diving the HTMS Chang combines history with rich marine biology. Descending onto the wreck, divers witness the superstructure emerge, gradually revealing the ship's immense dimensions, from its bridge and radar mast to its gun platforms. The warm Gulf waters ensure rapid marine colonization, continually enhancing its appeal as one of Southeast Asia's must-dive wrecks.

Dive site facts: HTMS Chang Wreck

Depth

12–34 m

Typical dive

30 m, 40–50 min

Current

Mild to moderate

Visibility

10–25 m

Water temperature

28–30°C

Entry

Boat

Level

Advanced Open Water, Wreck Diver for penetration

Dive type

Wreck, artificial reef, technical

Night dive

Possible

Region / port

Koh Chang / Gulf of Thailand

Coordinates

11.945, 102.365

Conditions & Currents

Currents at the HTMS Chang Wreck are generally mild, but can occasionally increase, requiring divers to be mindful of drift, particularly around the deeper sections and during penetrations. While the wreck is usually dived as a boat trip, conditions are typically calm enough for simple entry and exit. Visibility averages around 15 meters, but can extend up to 25 meters during peak season, with water temperatures consistently warm at 28-30°C. Divers should plan their descent and ascent carefully, using the wreck's structure for shelter if needed, and always consider the potential for moderate currents when planning gas consumption and bottom time, especially for deeper or penetration dives.

Marine life & sighting chances

Barracuda

common

Snapper

common

Batfish

common

Nudibranch

common

Scorpionfish

occasional

Grouper

occasional

Moray eel

occasional

Soft corals

common

Sponges

common

Anemones

common

Clams

occasional

Fusilier

common

Dive profile & how the dive runs

Your dive on the HTMS Chang typically begins with a descent along a mooring line to the wreck's superstructure. Recreational divers usually explore the upper decks and external areas, starting around 12-18 meters. You can circumnavigate the massive hull, observing the bridge, radar mast, and gun platforms. A common route involves swimming along the length of the vessel, taking in the scale and marine growth, before heading to the deeper sections around 30 meters where the propellers and rudder are located. Due to the depth and size, multiple dives are often required to fully appreciate the wreck. Penetration dives for appropriately trained divers explore internal spaces like the engine room and cargo holds. Safety stops are conducted on the ascent, often utilizing the mooring line or shallower parts of the wreck, before returning to the boat.

Underwater photography

The HTMS Chang offers abundant opportunities for wreck and wide-angle photography, capturing the immense scale of the 100-meter vessel and its dense fish schools. A wide-angle lens is essential for documenting the full ship profile, particularly the impressive superstructure and large external features. For macro enthusiasts, numerous nudibranchs, smaller invertebrates, and intricate coral growth provide excellent close-up subjects. Due to the depth and potential for lower visibility, external strobes are highly recommended to bring out the vibrant colors of the marine life and corals. When exploring the wreck's interior, a powerful video light or torch is crucial for illumination and to aid focusing. Maintaining excellent buoyancy is paramount to avoid disturbing sediments and ensuring clear shots, especially within the overhead environment.

Combine with nearby dive sites

• Hin Raab

  A nearby rocky reef with coral, turtles, and barracuda.

• Hin Tai Nam (Blueberry Hill)

  A twin-pinnacle reef featuring corals, a canyon, and turtles.

• Secret Reef

  A coral garden canyon dive site near Koh Chang.

• Hin Luk Bat

  A pinnacle dive with corals, groupers, and schooling fish.

Getting there & logistics

Access to Koh Chang usually begins with travel to Bangkok, followed by a 4-5 hour drive or bus to Trat, or a short flight to Trat Airport (TDX). From Trat, regular ferries connect to Koh Chang, taking 30-45 minutes. Once on the island, dive centers, primarily located on the west coast, organize boat trips to the HTMS Chang, typically as day trips. There are no national park fees specific to this wreck, but dive operators will charge for the boat trip and dive guiding. It is normally combined with other local Koh Chang reef dives.

Safety & environment

Diving the HTMS Chang requires advanced dive certification due to its depth and potential for currents. For wreck penetration, specific training and certification, such as TDI Advanced Wreck, are mandatory due to the overhead environment and associated risks. Divers must be proficient in buoyancy control to avoid entanglement or disturbing silt. The nearest recompression chamber is likely in Pattaya or Bangkok, meaning evacuation could be lengthy; therefore, comprehensive dive insurance is highly recommended. Always dive with a reputable local operator, adhere strictly to guide instructions, and avoid solo diving or exceeding training limits. Conservative dive planning, including gas management and decompression, is essential given the depth.

Who it suits — and who it doesn't

FAQ

HTMS Chang Wreck FAQ

Liveaboards diving HTMS Chang Wreck

These liveaboards may visit HTMS Chang Wreck on selected itineraries — the exact dive sites depend on departure, weather and conditions.

Mandarin Queen 9

Thailand

26 guests37.5 m

Manta Queen 8

Thailand

24 guests

$127/day

The Junk

Thailand

18 guests33 m

$163/day

Deep Andaman Queen

Thailand

23 guests30.5 m

$194/day

Explorer

Thailand

16 guests25 m

$150/day

Andaman

Thailand

20 guests26 m

$108/day

Stingray

Thailand

8 guests24 m

$245/day

Seatopia

Thailand

24 guests24 m