San Francisco Maru - Chuuk (Truk) Lagoon

The San Francisco Maru isn’t just a dive, it's a history lesson encased in rust, plummeting from 45m to a maximum of 65m. We love the feeling of descent here, dropping onto a deck still laden with Japanese Type 95 Ha-Go light tanks. It’s a genuine chill, seeing those turrets angled skyward, frozen in time. Below deck, there are trucks and mines – a truly haunting cargo. This is an expert dive, no question, and we’d suggest good buoyancy control is essential to avoid silting out the holds. Inside, the gloom presses in, only broken by the beam of a dive light revealing honeycomb groupers lurking in shadowy corners or the iridescent flash of a roundhead parrotfish darting past a porthole. Look closely at the deck plating; you’ll often spot curious ostrich gobies peeking out. The sheer scale and preservation make it one of our favourite deep wrecks in Chuuk, a tangible link to a pivotal moment.

Location: Chuuk (Truk) Lagoon, Micronesia, Central & South Pacific
Coordinates: 7.340000, 151.890000
Type: wreck
Maximum Depth: 45-65m
Difficulty: Expert

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 San Francisco 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 San Francisco 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