
Hammerhead Point (Irizaki)
Yonaguni · Japan
Open-water drift along the Kuroshio current off Cape Irizaki, the westernmost point of Japan, where scalloped hammerheads gather through winter — schools of 100 to 200 sharks are logged from January to March. There is no reef to hide behind: divers make a negative entry, drop fast and hover near 15–20 m in open blue water over a seabed close to 70 m, watching the current line for the massed sharks. Dive operator Kihachiro Aratake was scouting this hammerhead ground in 1986 when he came across the nearby Yonaguni Monument. Between shark passes the same current draws in dogtooth tuna, great barracuda and bigeye trevally, with the odd sailfish. Visibility often runs past 30 m, but winter north winds cut it back and regularly cancel boats.
Conditions
Depth
15 to 40 m
Advanced depths
Current
Can be moderate
Can pick up on the edge
Visibility
15 to 25 m
Clearest in the calm season
Water
21 to 29°C
3mm full or shorty
Month by month
| Month | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Water (°C) | 21 | 21 | 22 | 23 | 24 | 26 | 27 | 28 | 27 | 25 | 23 | 22 |
| Vis (m) | 20 | 20 | 20 | 20 | 15 | 15 | 15 | 15 | 15 | 15 | 20 | 20 |
| Current | Strong | Strong | Strong | Moderate | Moderate | Moderate | Moderate | Moderate | Strong | Moderate | Strong | Strong |
Your chances of seeing each animal
Scalloped hammerhead shark
Last confirmed Mar 15, 2026 · 45 records
Very likely
Most dives
Dogtooth tuna
Last confirmed Feb 23, 2026 · 1 records
Likely
About 6 in 10 dives
Great barracuda
Expected
Known here, not yet in recent logs
Bigeye trevally
Expected
Known here, not yet in recent logs
Indo-Pacific sailfish
Expected
Known here, not yet in recent logs
Gear