Clearest water

Clearest water

Last updated: May 25, 2020 at 2:55 am

80 m (262 ft) or the approximate visibility of distilled water. A few locations are claimed to equal the visibility of distilled water, including the Silfra Fissure in Iceland, the Weddell Sea (Antarctica), New Zealand’s Blue Lake (a.k.a. Rotomairewhenua), and some Mexican cenotes. Claims of visibility surpassing 80 metres anywhere are likely overstated. However, the Weddell Sea has the added distinction of being composed of seawater that is teeming with life, including plankton.

National Institute of Water and Atmospheric Research (NIWA).

W.W.C. Gieskes, C. Veth, A. Woehrmann and M. Graefe, EOS, 1987.

Witnessed by Diving Almanac & Book of Records official (Silfra, Iceland).

World’s clearest water | Tectonic dive and trolls in Iceland

Glacial water filtered underground is released into the Silfra fissure after a period of 30 to 100 years. Photo © Jeffrey Gallant | Diving Almanac

The entry dive stairway at Silfra. Photo © Jeffrey Gallant | Diving Almanac

Diving at Silfra in the best underwater visibility that I have ever seen. Photo © Jeffrey Gallant | Diving Almanac

Diving through the Cathedral, at Silfra. Photo © Jeffrey Gallant | Diving Almanac

Last bottleneck before entering the Lagoon, at Silfra. Photo © Jeffrey Gallant | Diving Almanac

Diving at Silfra, the Lagoon. Photo © Jeffrey Gallant | Diving Almanac

The exiting ladder in the Lagoon at Silfra. Photo © Jeffrey Gallant | Diving Almanac

Scientists in McMurdo Sound, Antarctica. Photo by Rob Robbins | NSF

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