Created June 17, 2021, 12:03 p.m.
Updated June 17, 2021, 12:03 p.m.

Colour The EyeOnWater colour app helps us to classify rivers, lakes, coastal waters, seas and oceans on it's colour (it can be used for both fresh and saline natural waters). The observations via the app are an extension of a long term (over 100 years) set of water colour observations made by scientists in the past. You can view them all together in the map application. Clarity Clarity observations are usually done by Secchi Disk, lowering a white disk in the water and measuring to what depth it is still visible. EyeOnWater has collected a large dataset of observations from the past, and this set has been extended by citizens and volunteer measurements contributed via the EyeOnWater app. All data is publicly available and additional viewing and access services are available upon request. The data can be used as time series to indicate changes in the water over time (e.g. from blue to green), but can also be used to validate remote sensing data. EyeOnwater was originally funded by the EU (FP7), but is currently funded by running spin-off citizen science concepts in Australia (EOW Australia for CSIRO) and in the Netherlands (e.g. for Waterplant monitoring).


The EyeOnWater website and free Apps help you to assess the Colour and Clarity of natural waters.

How to participate

Download the app, visit a water in your area and take observations.

Needed equipment

The EyeOnWater app. Extended with a Secchi disk if you want but this is not mandatory.

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