Sanko Maru
Rabaul · Papua New Guinea
The Sanko Maru is a fully intact Japanese freighter resting upright at 25 meters in Simpson Harbour, its holds still stacked with wartime cargo including truck chassis, aircraft parts, and ammunition crates. Dense schools of glassfish pulse through the companionways while large lionfish and batfish patrol the superstructure. Hard and soft corals have colonized every exposed surface over eight decades, turning a vessel of war into one of Papua New Guinea's most colorful artificial reefs.
Conditions
Depth
10 to 28 m
Open water and up
Current
Usually still
Can pick up on the edge
Visibility
20 to 30 m
Clearest in the calm season
Water
26 to 30°C
3mm wetsuit
Month by month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Water (°C) | 28 | 28 | 28 | 28 | 27 | 26 | 26 | 26 | 27 | 27 | 28 | 28 |
| Vis (m) | 10 | 10 | 12 | 15 | 18 | 20 | 20 | 20 | 18 | 15 | 12 | 10 |
| Current | Gentle | Gentle | Gentle | Still | Still | Still | Still | Still | Gentle | Gentle | Gentle | Gentle |
Your chances of seeing each animal
Lionfish
Last confirmed Jul 5, 2025 · 1 records
Likely
About 6 in 10 dives
Spine-Cheek Clownfish
Last confirmed Mar 16, 2026 · 1 records
Rare
Now and then
Reef Stonefish
Last confirmed Jul 5, 2025 · 1 records
Rare
Now and then
Clark'S Anemonefish
Last confirmed Mar 3, 2026 · 2 records
Rare
Now and then
Batfish
Expected
Known here, not yet in recent logs
Yellowfin Trevally
Expected
Known here, not yet in recent logs
Glassfish
Expected
Known here, not yet in recent logs
Blackspotted Puffer
Expected
Known here, not yet in recent logs
Gear