Koh Chang Wreck Dive: HTMS Chang Guide
Plan a Koh Chang wreck dive: who it suits, penetration vs. exterior, boat logistics, season and what to confirm before you book.
On this page
Last updated November 2026. The Koh Chang wreck dive centers on the HTMS Chang, one of the island's most popular dive sites. Most certified divers can look at it from the outside, and going inside takes extra training. This guide sits under our Koh Chang diving guide and covers who qualifies, what to ask operators, and how to plan the day.
Featured image: Kitfretz, CC BY-SA 4.0, via Wikimedia Commons.
The Koh Chang wreck dive in brief
HTMS Chang is the wreck most divers mean when they search for a Koh Chang wreck dive. Local dive centers rank it among the island's most popular sites. Wreck diving is one of the optional adventure dives in the Advanced Open Water course. Longer wreck dives are a common reason to add Nitrox. Exact depth, visibility and trip format differ by operator and by day. Ask the dive center for the maximum depth in meters and feet before you pay, and match it to your certification.
Who can dive the HTMS Chang wreck
Certification decides what you can do here. A Scuba Diver certification takes about 2 days and limits you to 12 m (39 ft) with a dive professional. That is a stepping stone, so ask the operator whether the wreck's depth fits it. Open Water and Advanced Open Water divers can usually plan exterior dives, subject to the operator's depth rules. Penetration belongs to divers with wreck training. Courses follow the standards on the PADI course pathway, and other agencies offer equivalents.
A Scuba Diver certification caps you at 12 m (39 ft) with a dive professional, so compare that with the wreck's depth before you pay.
| Your level | Typical wreck plan | Ask the operator |
|---|---|---|
| Not certified (Try Dive) | Usually not the wreck; a Try Dive is a shallow introduction | Whether any wreck option exists for you |
| Scuba Diver (12 m / 39 ft limit) | Depends on the wreck's depth | Maximum depth on this trip |
| Open Water | Exterior dive if depth rules allow | Depth limit and guide ratio |
| Advanced Open Water | Exterior dive; wreck can be one of your adventure dives | Whether the wreck dive counts toward the course |
| Wreck Diver specialty | Penetration with a qualified guide | Which areas are open and what gear is required |
| Non-diver | Snorkeling elsewhere around the island | Boat seats for non-divers |
Exterior dive vs. penetration
An exterior dive keeps you in open water along the hull and decks. A penetration puts a solid overhead between you and the surface. That brings silt, tight exits and a longer route back to open water. Dedicated video coverage exists for planning HTMS Chang penetrations, which shows how much preparation divers put in. The Wreck Diver course teaches you how to explore wrecks safely, and it is the route to penetration.
- Skip penetration unless you hold wreck training and your guide has led it before.
- Skip it if you are not comfortable with your air consumption and buoyancy.
- Skip it when visibility drops or the current picks up.
- Skip it if the operator cannot explain the exit route and turn-around rule.
Getting there and trip format
Departure pier, transit time and dives per trip vary by operator. Ask your dive center for the current schedule.
Cost and what's included
Operators price wreck trips differently, so compare what each quote covers. Ask for the full price in baht and the items below. Prices and hours checked November 2026 where operators publish them.
- Fun dive fee for certified divers.
- Wreck Diver course fee, if you plan to penetrate.
- Nitrox add-on, useful for longer wreck dives.
- Equipment hire, if you do not bring your own.
- Any park or marine fees, and boat transfers.
Best time and conditions
Visibility, current and weather decide whether the wreck is a good dive on a given day. Sea conditions follow the monsoon pattern, and trips can be cancelled when it turns rough. Read our Koh Chang diving season guide before you pick dates. Book flexible days if your schedule allows, and ask what happens to your payment if the boat does not run.
Mistakes to avoid
Most problems come from assumptions made before the boat leaves.
- Booking a penetration dive without wreck training.
- Assuming Nitrox is required. It is a suggestion for longer dives, not a rule.
- Skipping questions about the guide's experience on this wreck.
- Underestimating transit time and planning a tight schedule around it.
Other dives and non-diver options
The wreck works best as a highlight of a multi-dive day, not the only reason to book. Compare it with the island's reef sites in our Koh Chang Dive Sites: Wrecks, Reefs & Koh Rang overview. Hin Luk Bat Dive Site, Koh Chang: Routes, Depth, Season has its own site guide. For a different setting, look at Koh Rang Islands, Koh Chang: Snorkeling Day Trip Guide. Divers heading farther can read about diving around Koh Kood. Friends who do not dive can join a snorkeling day instead. Our Koh Chang snorkeling guide covers the reefs and fish they can see from the surface.
Notes for your next dive trip
Optional updates to our Thai diving guides.
You might also like
Continue reading
More guides you'll find useful
