
American Tanker Wreck
Mariana Islands (Guam & Saipan) · United States
The American Tanker is a WWII-era fuel transport vessel resting on its starboard side in 32 m of water off Guam's north-east coast, its hull encrusted over 80 years of colonisation by black coral trees, enormous sea fans, and a thick carpet of encrusting sponges that have transformed the wreck into an artificial reef of extraordinary diversity. The cargo tanks are penetrable by experienced divers and contain intact gauges, valves, and pipe work that document mid-century industrial engineering, while the outer hull has been colonised by lionfish, scorpionfish, batfish, and large grouper that use the wreck as a permanent home rather than a transient resting point.
Conditions
Depth
12 to 35 m
Advanced depths
Current
Can be moderate
Can pick up on the edge
Visibility
18 to 28 m
Clearest in the calm season
Water
27 to 31°C
3mm wetsuit
Month by month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Water (°C) | 27 | 27 | 27 | 28 | 28 | 29 | 29 | 29 | 29 | 29 | 28 | 27 |
| Vis (m) | 25 | 25 | 25 | 25 | 25 | 20 | 18 | 15 | 15 | 20 | 22 | 25 |
| Current | Gentle | Gentle | Gentle | Still | Still | Still | Moderate | Moderate | Moderate | Gentle | Gentle | Gentle |
Your chances of seeing each animal
African Giant Snail
Last confirmed Jul 3, 2026 · 52 records
Almost always
Nearly every dive
Purple Hermit Crab
Last confirmed Jun 18, 2026 · 47 records
Almost always
Nearly every dive
Pacific Bullethead Parrotfish
Last confirmed Feb 28, 2026 · 31 records
Very likely
Most dives
Scorpionfish
Last confirmed Sep 30, 2025 · 2 records
Likely
About 6 in 10 dives
Indo-Pacific Man-O-War
Last confirmed Feb 7, 2026 · 4 records
Sometimes
About 1 in 3 dives
Batfish
Expected
Known here, not yet in recent logs
Giant Grouper
Expected
Known here, not yet in recent logs
Gear