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  • Official comment
    David Velasco

    Hi Naeem

    That does seem counter-intuitive, doesn't it?  After all, the deeper the water, the more energy an ADCP needs to put into the water in order to reach the full range.  But recall that the Eco is a self-configuring ADCP, and a controlling parameter is the velocity precision of each sample.  You can learn more about this in this paper (, but the short answer is that for every sample the Eco attempts to return a velocity precision that is 1 cm/s or better, regardless of the environment that it is in.  When the water level is shallow, the thickness of each depth layer is small, which means the volume of water being ensonified is small and therefore the Eco needs to average a larger number of pings to achieve the target precision.  More pings = more power.  In deeper water, the layers are thicker and therefore the Eco can achieve target precision using fewer pings than when the water is shallow.  Less pings = less power = longer battery life.

    In fact, if you could see the Eco's LED light while underwater in, say, 5 m of water and then in, say, 20 m of water, you would see that it stays blinking for a longer period of time at 5 m than at 20 m.  And while you're there, you could also take a selfie next to your Eco and send it to us.  We love seeing users with their Eco :-)

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