Raw EK60 echosounder data: Swart seamount, British Indian Ocean Territory 2015

These data consist of raw uncalibrated 38 and 120 kHz echosounder observations collected during a pelagic survey of the Chagos archipelago MPA (January 2015). Observations were collected from a pole-mounted system (transducers were fixed at a depth of 3m). Data include several transects recorded during the 19th January at the Swart seamount site (close to Diego Garcia). A calibration was conducted prior to the survey. Resultant transducer peak gain (G0) and Simrad correction factor (Sa) values were as follows: 38 kHz (power = 1000 W; pulse duration = 1.024 ms; G0 = 20.97 dB; Sa = -0.62 dB) and 120 kHz (power = 250 W; pulse duration = 1.024 ms; G0 = 24.5 dB; Sa = -0.29 dB).