CPIES

The inverted echo sounder (IES) measures acoustic echo time (τ) from the sea bed to the sea surface. The "CPIES" is an IES with added sensors to measure both current (50 m above the sea floor to avoid the bottom boundary layer) and bottom pressure. The instruments sample hourly and have telemetry systems that enables data to be downloaded to a computer on a nearby ship.

Photo by Shane Elipot