HEIHAN MARU - Chuuk (Truk) Lagoon

The Heihan Maru, she's a big girl. At 155 metres, you’ll be doing multiple dives to properly take her in, and we think she’s absolutely worth it. What makes her a standout for us isn't just the sheer scale, it's the sheer variety. We love dropping down into the immense holds, where you can still make out the ghostly outlines of tanks and other cargo. It’s a completely different vibe from the engine room, which feels almost cathedral-like with the light shafts cutting through the gloom. You’ll find something new on every pass – a porcelain toilet still intact in the crew quarters, or a scattering of gas masks. For marine life, keep an eye on the bow and stern sections, especially around the masts. They’re usually draped in soft corals, and you’ll often find schools of fusiliers swirling so thick they practically block out the sun. It’s also a good spot for lionfish and the occasional reef shark cruising by. Our best advice? Take your time. Don't rush through; there's too much history here to just tick off the big items. Try to hit the holds around midday for the best light penetration. This is a site that truly rewards careful, repeated exploration, a must for anyone serious about wreck diving.

Location: Chuuk (Truk) Lagoon, Micronesia, Central & South Pacific
Coordinates: 7.383889, 151.861390
Type: wreck
Maximum Depth: 0m

Best Time to Dive in Chuuk (Truk) Lagoon

The warmest water temperatures in Chuuk (Truk) Lagoon occur in January, averaging 28.9°C. The coolest conditions are in December at 28.9°C.

Monthly Water Temperatures

January: 28.9°C (air: 27.8°C)
February: 28.9°C (air: 27.7°C)
March: 28.9°C (air: 27.5°C)
April: 28.9°C (air: 27.5°C)
May: 28.9°C (air: 27.7°C)
June: 28.9°C (air: 27.5°C)
July: 28.9°C (air: 27.5°C)
August: 28.9°C (air: 27.7°C)
September: 28.9°C (air: 27.7°C)
October: 28.9°C (air: 27.9°C)
November: 28.9°C (air: 27.9°C)
December: 28.9°C (air: 27.9°C)

Nearest Dive Centres to HEIHAN MARU

Marine Life in Chuuk (Truk) Lagoon

Home to 213 recorded species including 133 reef fish, 36 hard corals, 17 sea cucumbers, 12 sea snails & nudibranchs, 5 sharks & rays, 4 clams & mussels.

Notable Species

Bristle-toothed Surgeonfish (Ctenochaetus striatus) - Reef Fish
Bleeker's Parrotfish (Chlorurus bleekeri) - Reef Fish
Bullethead Parrotfish (Chlorurus sordidus) - Reef Fish
Long-nosed Parrotfish (Hipposcarus longiceps) - Reef Fish
Blunt-head Parrotfish (Chlorurus microrhinos) - Reef Fish
Small giant clam (Tridacna maxima) - Clams & Mussels
Saddled Parrotfish (Scarus dimidiatus) - Reef Fish
Clown Tang (Naso lituratus) - Reef Fish
Black sea cucumber (Holothuria atra) - Sea Cucumbers
Greenfish (Stichopus chloronotus) - Sea Cucumbers
Schlegel's Parrotfish (Scarus schlegeli) - Reef Fish
Roundhead Parrotfish (Scarus globiceps) - Reef Fish
Dusky Parrotfish (Scarus niger) - Reef Fish
Blackspotted Sea Cucumber (Pearsonothuria graeffei) - Sea Cucumbers
Batavian Parrotfish (Scarus psittacus) - Reef Fish
Crown of thorns starfish (Acanthaster planci) - Starfish
Sea chub (Kyphosus cinerascens) - Reef Fish
Foxface (Siganus vulpinus) - Reef Fish
Banded maori wrasse (Cheilinus fasciatus) - Reef Fish
Unicornfish (Naso annulatus) - Reef Fish

Recommended Packing List for HEIHAN MARU

Based on average water temperature of 28.9°C.

Shorty or Rashguard - warm 29°C water needs minimal exposure protection
Mask - essential for every dive
Fins
BCD - buoyancy compensator
Regulator - your most safety-critical piece of gear
Dive Computer - tracks depth, time, and NDL
Surface Marker Buoy (SMB) - essential for boat pickups
Dive Torch - useful for crevices and colour at depth
Underwater Camera - capture your diving memories