Tago, Futone & Shirasaki Visibility Comparison — Hidden Gems
2026-03-16
While IOP, Futo, Kumomi, and Mikomoto get the spotlight, West Izu's Futone, Tagojima, and Tago have real potential. Wakayama's Shirasaki achieves R²=0.60 AI prediction accuracy from just 538 observations. We compare these under-the-radar sites with real data.
4-Site Comparison
Advanced drift site. Nearly matches IOP (13.8m). Winter Jan 14.8m is peak
Summer-only offshore point. Data only May–Sep. Sep 11.9m is best
Distinctive white limestone seabed. Winter Jan 13.2m is best. AI prediction R²=0.60
Harbor-side site. Winter reaches 11m but summer drops to 5–6m
Monthly Visibility
| Site | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Futone | 14.8 | 14 | 11.9 | 11.4 | 10.4 | 12.1 | 10.9 | 11.2 | 13.2 | 13.2 | 12.3 | 12.9 |
| Tagojima | — | — | — | — | 9.9 | 11.5 | 10 | 10.9 | 11.9 | — | — | — |
| Shirasaki | 13.2 | 12.8 | 10.9 | 9.9 | 8.4 | 8.5 | 7.8 | 9 | 8.6 | 9.8 | 9.8 | 11.6 |
| Tago (Harbor) | 11.5 | 10.2 | 8.5 | 5.6 | 5.6 | 6.6 | 6.4 | 6.2 | 7.7 | 5.3 | 6.7 | 9.1 |
Key Highlights
Futone Has IOP-Class Potential
Futone's 12.3m annual average ties for #2 on the Izu Peninsula (with Mikomoto), behind only IOP (13.8m). January's 14.8m is top-class for Izu's offshore points. Note: drift-only for advanced divers, and often closed due to sea conditions.
Shirasaki: AI's Star Pupil
Shirasaki's AI prediction R²=0.60 is remarkably high for just 538 observations (IOP achieves R²=0.82 with 3,151). Shirasaki's visibility correlates strongly with weather conditions (wind direction, wave height), making forecasts reliable.
Tago Transforms in Winter
Tago (Harbor) averages just 8.3m annually, but January reaches 11.5m — nearly double summer's 5–6m. It has one of West Izu's largest seasonal swings. Winter Tago is a hidden gem.
About the Data
Futone 936 / Tagojima 198 / Shirasaki 538 / Tago 159 observations (2006–Mar 2026). Tagojima: May–Sep only (closed in winter).
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