Wind Direction Visibility Guide: Which Wind Clears Your Dive Site?
2026-03-16
"North wind means good visibility" — common diver wisdom, but it actually reverses depending on the site. We matched 46,000+ visibility observations with weather data to analyze wind direction effects at 10 sites. The impact reaches up to 3.1m — significant for dive planning.
Visibility by Wind Direction
| Site | N | E | S | W | Best | Gap |
|---|---|---|---|---|---|---|
| Ito | 17.1m | 15.1m | 14.4m | 15.8m | N | 2.7m |
| Kerama | 18.2m | 19.5m | 20.5m | 19.4m | S | 2.3m |
| IOP | 14.5m | 12.8m | 11.9m | 15m | W | 3.1m |
| Shirasaki | 11.6m | 10.4m | 8.8m | 10.3m | N | 2.8m |
| Kushimoto | 12.4m | 12.2m | 11.9m | 11.3m | N | 1.1m |
| Mikomoto | 12.4m | 12.8m | 12.7m | 11.8m | E | 1m |
| Kashiwajima | 13.2m | 12.6m | 13.2m | 13.4m | W | 0.8m |
| Tajiri | 10m | 9.1m | 9.3m | 9.4m | N | 0.9m |
| Echizen | 9m | 9.1m | 8.8m | 8.4m | E | 0.7m |
| Yonaguni | 24m | 24.4m | 24.9m | 25.9m | W | 1.9m |
Blue = best wind direction. Gap = difference between best and worst wind
Regional Patterns
Pacific Coast: North & West Winds Clear
IOP (W 15.0m, +3.1m gap), Ito (N 17.1m, +2.7m), Shirasaki (N 11.6m, +2.8m). Winter high-pressure pattern (continental high → NW wind) pushes offshore clear water toward the coast, displacing plankton-rich coastal water.
Okinawa: South & West Winds Clear
Kerama (S 20.5m, +2.3m), Yonaguni (W 25.9m, +1.9m). Okinawa sites improve when warm oceanic water flows from the south. North wind (winter monsoon) brings turbid continental shelf water — counterproductive.
Sea of Japan: Minimal Wind Effect
Echizen (0.7m gap) and Tajiri (0.9m gap) show minimal wind effect. Sea of Japan visibility is driven more by season (temperature, plankton) than wind direction.
Practical: Using Weather Forecast Winds for Diving
- West/NW wind forecast for Izu → Target IOP or Ito (+2–3m improvement)
- South wind day in Okinawa → Kerama boat tour is best (expect 20.5m)
- Avoid Shirasaki on south wind days → drops to 8.8m (north wind: 11.6m)
- Echizen/Tajiri: don't worry about wind → 0.7–0.9m gap is negligible
About the Data
46,000+ visibility observations matched with Open-Meteo wind direction data. Wind classified into 4 quadrants: N (315–45°), E (45–135°), S (135–225°), W (225–315°).
🌊 Calculators for divers
Wetsuit thickness, air consumption, nitrox MOD, dive weights — all calculated on your device, so they work with no signal on the boat.
See the tools →