Ito vs Akinohama: Tokyo Area's Clearest Dive Sites Compared
2026-03-16
Ito (Tateyama, Chiba) and Akinohama (Izu Oshima) are high-visibility dive sites within 2 hours of Tokyo. Ito averages 15.9m (1,985 obs) vs Akinohama's 14.3m (1,309 obs) — Ito is +1.6m higher. But Akinohama's seasonal range of just 1.7m makes it Japan's most stable dive site. We compared the data to help you choose.
15.9m
Ito avg
14.3m
Akinohama avg
5.6m
Ito range
1.7m
Akinohama range
Monthly Visibility Comparison
| Month | Ito(m) | Akinohama(m) | Diff |
|---|---|---|---|
| Jan | 18.8m | 15.1m | Ito +3.7 |
| Feb | 18.2m | 14.8m | Ito +3.4 |
| Mar | 17m | 14.5m | Ito +2.5 |
| Apr | 15.5m | 14m | Ito +1.5 |
| May | 14.2m | 13.8m | Ito +0.4 |
| Jun | 13.8m | 13.5m | Ito +0.3 |
| Jul | 13.5m | 13.8m | Aki +0.3 |
| Aug | 13.2m | 14m | Aki +0.8 |
| Sep | 14.5m | 14.2m | Ito +0.3 |
| Oct | 15.8m | 14.5m | Ito +1.3 |
| Nov | 17m | 14.8m | Ito +2.2 |
| Dec | 18m | 15m | Ito +3.0 |
Two Contrasting Characteristics
Ito: A Winter Visibility Champion
Ito boasts 17-18.8m visibility in winter (Dec-Feb). January's 18.8m is among the best near Tokyo. Its geography allows clear Kuroshio branch water to flow in. However, summer drops to 13m range, creating a 5.6m seasonal swing.
Akinohama: Japan's Most Stable Site
Akinohama's seasonal range is just 1.7m (13.5-15.1m) — the smallest among Japan's major dive sites. You can expect around 14m visibility any time of year, making it extremely predictable. Izu Oshima's geography ensures stable water supply from the open ocean.
Access Comparison
Ito (Tateyama, Chiba)
- About 2 hours by car from Tokyo
- Via Aqua-Line through Kisarazu
- Train: Bus/taxi from Tateyama Station
Akinohama (Izu Oshima)
- About 1h 45min by high-speed ferry from Takeshiba
- About 25 min from Chofu Airport
- Rental car recommended on island
When to Choose Which
Choose Ito When
- Want 18m+ winter visibility
- Easy car access preferred
- Want to see shark (banded houndshark) aggregations
Choose Akinohama When
- Want reliable visibility any season
- Detailed macro photography
- Combine with island sightseeing
About the Data
Analysis based on real dive log data from Ito (1,985 obs) and Akinohama (1,309 obs). Visibility uses daily average values.
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