Where Can You Guarantee 15m+ Visibility? Probability Ranking

2026-03-16

"We went but it was murky" — a diver's worst disappointment. Which sites virtually guarantee 15m+ visibility? From 46,000+ observations, we calculated the probability of 15m+ at each site. Sites above 80% mean clear water 4 out of 5 times.

15m+ Probability Ranking

S
Yonaguni99.4%

4,797/4,826 obs

S
Ishigaki96.5%

1,421/1,473 obs

A
Yakushima92.5%

147/159 obs

A
Amami92.3%

800/867 obs

A
Kerama87.1%

1,354/1,554 obs

B
Hachijojima77.1%

262/340 obs

B
Akinohama75.2%

984/1,309 obs

B
Ito65%

1,291/1,985 obs

C
Shirahama58.6%

361/616 obs

C
Sado53.5%

175/327 obs

C
Kashiwajima44.4%

686/1,544 obs

C
IOP42.3%

1,376/3,252 obs

D
Koganezaki37.2%

413/1,110 obs

D
Mikomoto34.4%

779/2,263 obs

D
Futo25.7%

898/3,495 obs

D
Kushimoto20.6%

652/3,172 obs

Tier Explanation

S (90%+): Near-Guaranteed

Yonaguni, Ishigaki, Yakushima, Amami. 9/10 dives are 15m+. Okinawa/island power.

A (75-90%): High Probability

Kerama, Hachijojima, Akinohama. 3/4 dives are 15m+. Islands and stable sites.

B (50-75%): More Than Half Clear

Ito, Shirahama, Sado. Pick the right season for better odds. Winter is best.

C-D (<50%): Seasonal Only

IOP 42%, Kushimoto 21%, Futo 26%. Winter-only for 50%+. Summer expectations low.

About the Data

46,000+ observations from sites with 100+ data points. 15m+ threshold based on (min+max)/2.

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