> ## Content Index
> Fetch the complete content index at: https://www.techdiving.com.au/llms.txt
> Use this file to discover other available public pages before exploring further.

# Chuuk Lagoon
- URL: https://www.techdiving.com.au/chuuk-lagoon/
- Published: 2026-09-30T05:42:43.000Z
- Updated: 2026-09-30T05:42:43.000Z
- Description: A Japanese fleet sunk in 1944 lies in the warm water of a Micronesian lagoon. It's one of the world's great wreck-diving destinations, and one that deserves respect.
- Author: Tech Diving AU
- Tags: Locations, Wreck, Deep/Trimix, #Import 2026-09-30 15:24

Site facts

Location

Chuuk State, Federated States of Micronesia

Type

Wreck

Depth

Shallow wrecks from about 10 m; deeper wrecks to 60 m and beyond

Water

About 28–30 °C

Access

Liveaboards and land-based operators

Typical gas

Nitrox on shallower wrecks; trimix or CCR on deeper ones

Remote location. Check the current status of recompression facilities and evacuation options before you travel.

In February 1944, US carrier aircraft attacked the Japanese base at Truk Lagoon in an operation codenamed Hailstone. Dozens of ships and hundreds of aircraft were destroyed. Today the lagoon, now known as Chuuk, holds one of the largest collections of Second World War wrecks anywhere.

## The wrecks

Many wrecks are cargo ships converted to military use, still holding their loads: trucks, aircraft parts, ammunition, and everyday items from the crews. Some sit in shallow water and suit recreational divers. Others are deeper and draw technical divers.

The *San Francisco Maru* is often named as the lagoon's signature technical dive. It lies deep, with tanks on its deck, and requires planning for depth, narcosis and decompression.

## Penetration

Much of the appeal of Chuuk is inside the wrecks: holds, engine rooms and passageways. That's also where the risk is. Silt builds up quickly, structures are decaying, and routes can be confusing. Line-laying, gas planning and wreck penetration training all apply here.

## Respect and responsibility

These are war graves. Human remains are still found on some wrecks, and many hold unexploded ordnance. Taking anything is illegal and disrespectful. Most operators brief divers on this carefully, and some wrecks have restrictions.

The wrecks are also deteriorating. Corrosion and fuel oil leaks are ongoing concerns, and some structures that were safe to enter years ago may not be now.

## Planning notes

- Chuuk is remote. Build in extra time for travel, and carry spares for critical equipment.
- Check how helium, oxygen and sorb supplies are managed by your operator well before arrival.
- Warm water makes long decompressions more comfortable, but it's easy to become dehydrated in the tropics.
- Plan conservatively. Evacuation from Chuuk to a major hospital is a long journey.