Photo: NIR HIMI / Unsplash
Truk Lagoon
Truk Lagoon (now Chuuk) is a wreck-diving destination first and a reef destination a distant second. In February 1944 the US carrier raid Operation Hailstone sank most of the Japanese fleet anchored here; more than 40 ships and dozens of aircraft still sit on the lagoon floor, many with cargo holds full of tanks, trucks, aircraft, mines and shells. The wrecks are what you come for. Marine life is real but modest: soft corals and anemones encrust the shallower hulls, with reef fish, the odd reef shark, barracuda and turtles. Depths vary enormously. Shallow wrecks like the Fujikawa Maru and Shinkoku Maru suit Advanced Open Water divers, while the celebrated deep wrecks such as the San Francisco Maru (42 to 64m) are technical, decompression dives. Nitrox is close to standard here and wreck-penetration training is needed for the engine rooms and holds. Water is warm year-round, roughly 28 to 30C, and the lagoon is sheltered, so currents are usually mild. Almost all diving is by liveaboard, though a land-based option with day boats exists. Many operators and divers treat the wrecks as war graves; human remains are present on some.
What makes it special
- The largest concentration of WWII shipwrecks in the world: 40-plus Japanese vessels sunk in Operation Hailstone, February 1944, many with intact cargo
- Holds packed with wartime cargo: tanks, trucks, aircraft, artillery, mines and shells still in place inside the San Francisco Maru, Nippo Maru and others
- Soft corals, anemones and sponges encrusting the shallower hulls like the Fujikawa Maru and Shinkoku Maru
- A rare pairing of easy sheltered recreational wrecks and serious deep technical wrecks in one small lagoon
Price range
$$–$$$
Trip length
7–10 days
Diver level
Advanced open water
Trip type
Liveaboard, Land based
Price is per person for a typical trip, excluding international flights ($$ $2,000–4,000 to $$$ over $4,000).
Liveaboard trips (Truk Master, SS Thorfinn, Odyssey) typically run 7 to 10 nights and commonly land around $3,000 to $5,500 per person depending on boat and cabin, excluding flights. The land-based option (Blue Lagoon Resort / Truk Stop Hotel with day boats) is cheaper per day. International airfare via Guam is a significant added cost and the island-hopper routing is the real expense in time and money, not the diving itself.
Best time to dive
- Current
- Mild
- Water temp
- 28–30°C (coldest Jan, warmest Mar)
- Visibility
- 15–40m — Commonly 15 to 40m; clearest in the drier months roughly December to April. The lagoon is sheltered, so viz is more affected by plankton and runoff than by swell.
- Getting there
- Moderate — Reachable but with some friction: 1 domestic flight.
- Experience
- Advanced Open Water covers the shallower wrecks (roughly 9 to 30m) and reaches an estimated 95% of the commonly dived hulls, per operators. But the best-known deep wrecks are technical: the San Francisco Maru (42 to 64m) and Aikoku Maru (40 to 64m) are decompression, mixed-gas dives needing trimix and CCR or extended-range training. Entering engine rooms and cargo holds requires wreck-penetration training and it carries real risk. Nitrox is close to mandatory to get useful bottom time at these depths and is offered as standard by most operators.
Nearest airports
- TKK — Chuuk International Airport (Reached on United's Micronesia island-hopper, almost always via Guam (GUM); Guam itself is the long-haul hub from Asia, Honolulu or the US mainland. Liveaboards and the land-based resort board on Weno island, a short drive from the airport.)
Permit required
Chuuk State levies a lagoon/wreck dive permit fee, collected via operators; the wrecks sit within a protected area and removing artifacts is illegal, with fines and possible jail. Confirm the current fee with your operator.
Chuuk State dive/permit fee, typically bundled by the operator; amount not independently verified here.
Marine life
Sightings are never guaranteed — the bars show typical likelihood by month.
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Occasional around the wrecks and lagoon passes; not the reason to come here.
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Occasionally seen cruising the wrecks and shallow reef patches.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Resident in the holds, portholes and wreckage of most ships.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Regularly hang over the larger hulls and superstructures.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Reliable on the anemone-covered shallow wrecks.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Schools hang around the superstructures of the larger wrecks.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
Frequently seen tucked into wreckage. Native to this region, so a normal resident rather than a pest.
| Month | Likelihood |
|---|---|
| January | occasional |
| February | occasional |
| March | occasional |
| April | occasional |
| May | occasional |
| June | occasional |
| July | occasional |
| August | occasional |
| September | occasional |
| October | occasional |
| November | occasional |
| December | occasional |
Seen resting under and around some wrecks. Truk is not a shark destination; encounters are incidental.
| Month | Likelihood |
|---|---|
| January | commonly seen |
| February | commonly seen |
| March | commonly seen |
| April | commonly seen |
| May | commonly seen |
| June | commonly seen |
| July | commonly seen |
| August | commonly seen |
| September | commonly seen |
| October | commonly seen |
| November | commonly seen |
| December | commonly seen |
The signature marine feature of the shallow wrecks; best developed on the well-lit upper structures.
Dive sites
Worth knowing before you book
- Getting here is a long haul: nearly everyone routes through Guam on United's multi-stop island-hopper, and delays or a missed connection can cost a day.
- The signature deep wrecks (San Francisco Maru, Aikoku Maru) are technical decompression dives beyond 40m; recreational divers see the shallow-to-mid wrecks only.
- The wrecks are war graves. Over 4,500 Japanese died in the raid and human remains are present on some hulls; divers are asked to treat them with respect, and artifact removal is illegal.
- This is wreck diving, not a big-animal destination. Expect soft coral and reef fish, not schooling sharks or manta aggregations.
- Penetration into engine rooms and holds carries genuine risk (silt-outs, entanglement, overhead) and requires wreck training; it is not for the untrained.
Sources & last checked
Checked July 2026
This is a researched draft, not yet human-verified. The seasonality and logistics are drawn from the sources below — confirm specifics (permits, fees, closures) with an operator before you book.
- How deep are the Truk Lagoon wrecks? — Master Liveaboards
- Truk Lagoon Wrecks (The Deepest, Biggest, & Most Popular Wrecks) — Scuba Diving Earth
- Truk Lagoon Human Remains (Is Truk Lagoon Ghost Fleet Haunted?) — Scuba Diving Earth
- Diving in Chuuk (Truk) Lagoon — PADI
- A Wreck in Depth - The San Francisco Maru — The Dirty Dozen Expeditions
- The Best Time to Dive Truk Lagoon — Master Liveaboards
- Island Hopper — Wikipedia
- Truk Lagoon Diving, Truk Stop Hotel — Truk Stop Hotel
- Liveaboards in Truk Lagoon, Micronesia — LiveAboard.com
Note on the data: Wreck depths corroborated across Master Liveaboards and Scuba Diving Earth. diverLevelMin set to advanced_open_water for the region because shallow-to-mid wrecks dominate and reach an estimated 95% of commonly dived hulls, with a precise note that the marquee deep wrecks (San Francisco Maru, Aikoku Maru) are technical/deco and holds require wreck-penetration training and nitrox. War-grave status is nuanced: the site is widely treated as a Japanese war grave and human remains are present, though sources note the local government's formal legal recognition is ambiguous; artifact removal is illegal. Coordinates are approximate lagoon-centre positions. Permit fee amount not independently verified. Water temperature is near-flat year-round per operator sources, not measured per-month. Water temperature: Near-equatorial and effectively flat year-round: operators cite a norm of 28 to 30C (82 to 86F) with very little seasonal variation. Monthly min/max here reflect that narrow band, not a genuine seasonal swing. A 3mm suit is usually enough, though technical divers doing long deco hangs often want more. Access: The remoteness is in the flights, not the transfer. Chuuk airport (TKK) to the wharf/resort on Weno is a short drive, roughly 15 to 30 minutes. The wrecks lie inside the sheltered lagoon, so boat rides to sites are short, commonly 15 minutes to an hour, with no open-ocean crossing. Getting to Chuuk is the hard part: United's island-hopper runs via Guam, and the Guam-Chuuk leg (counted here as one domestic hop) is itself sometimes a multi-stop segment via Pohnpei. Guam is reached by long-haul from Asia, Honolulu or the US mainland. Most diving is by liveaboard (Truk Master, SS Thorfinn, Odyssey), but a land-based option with day boats exists (Blue Lagoon Resort / Truk Stop Hotel), so the region is not liveaboard-only. Independently verified 2026-07-20 (confidence medium).