Unkai Maru - Chuuk (Truk) Lagoon

The Unkai Maru, she's a different beast from some of the other deep boys in Chuuk. Sitting in shallower water, she’s a perfect warm-up, or a brilliant second dive, offering heaps of penetration for those qualified. We love dropping into her holds, finding stacks of ceramic tiles, rows of sake bottles, and even some small trucks and jeeps still lashed down. The light plays beautifully through the openings, illuminating the ghostly cargo, and honestly, the sheer volume of stuff still onboard is genuinely striking. Outside, the deck guns are crusted with corals, home to schools of snapper and barracuda. Look closely, and you’ll spot nudibranchs tucked into crevices. The shallower depth means longer bottom times, giving you plenty of opportunity to explore the bridge or the engine room – definitely don’t skip the engine room, it’s remarkably intact. It’s not just a history lesson; it’s a living reef too. Our pick for a less demanding, but still utterly compelling, Chuuk experience.

Location: Chuuk (Truk) Lagoon, Micronesia, Central & South Pacific
Coordinates: 7.322500, 151.884500
Type: wreck

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 Unkai 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 Unkai 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