Dive Sites with the Biggest Min-Max Visibility Spread — Data Ranking

2026-03-15

Dive shop logs record visibility as a range like '8–15m'. A larger spread means visibility varies dramatically depending on depth and location within the site. We ranked 46,000+ observations by this min-max spread.

Largest Spread Top 10

#1Mikomoto(avg 12.3m / 2,263 obs)

6.1m

Offshore drift site. Strong currents create big depth/location differences. Summer (Jul 8.1m spread) peaks

#2Hachijojima(avg 17.1m / 338 obs)

5.6m

Direct Kuroshio hit causes high variability. Sep avg 21.9m but 11.2m spread — Japan's largest

#3Koganezaki(avg 13.5m / 1,110 obs)

4.6m

Complex West Izu topography. Shallow and deep areas within the site differ significantly

#4IOP(avg 13.8m / 3,151 obs)

Summer spread widens (Jul 6.7m). Plankton density differs between surface and mid-water

#5Tajiri(avg 9.4m / 1,392 obs)

San'in topography site. Aug spread 6.2m — cave interior vs open water differ

#6Tagojima(avg 10.9m / 198 obs)

3.6m

Offshore pinnacle in West Izu. Drift diving with big depth changes

#7Futone(avg 12.3m / 936 obs)

3.3m

Advanced drift off Osezaki. Current-dependent visibility

#8Hirasawa(avg 8.8m / 2,694 obs)

3.3m

Beginner spot but sandy bay floor — fin kicks stir up sediment

#9Shirasaki(avg 10.3m / 538 obs)

Wakayama limestone site. Different water masses at shallow vs deep

#10Kushimoto(avg 11.9m / 3,172 obs)

2.9m

Large site with multiple points. Offshore vs inner bay differences

Smallest Spread Sites (Consistent)

Yonaguni

avg 24.5m

Osezaki Point

2.1m

avg 10.5m

Osezaki Open

2.2m

avg 10.6m

Futo

2.5m

avg 11.5m

Yonaguni averages Japan's best 24.5m with only 2.0m spread — indicating uniformly clear water at all depths. Futo (2.5m spread) is also very consistent, meaning 'what you expect is what you get.'

What Spread Tells You

Large = Varies by Depth & Current

At offshore sites like Mikomoto and Hachijojima, visibility varies with current direction and depth. Murky shallows with clear mid-water is common.

Small = Uniform Water Mass

Sites like Yonaguni and Futo have uniform water — visibility barely changes with depth. What you see at the surface matches what you'll find underwater.

Impact on Photography

Wide-angle photography benefits from uniform visibility (low spread). Macro shooting is less affected by spread — so Mikomoto works fine for macro.

About the Data

Calculated from 46,000+ observations where both min and max visibility were recorded. Sites with 100+ observations included. Spread = mean(max − min).

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