The R/V Hugh R. Sharp is equipped with a Reson 7125 SVP2 (200/400 kHz) multibeam echosounder installed on a drop keel and an Applanix POS-MV 320 positioning and attitude system. Traditionally, survey planning and data acquisition are handled using Hypack HYSWEEP software installed on the RESON acquisition machine. These systems were reviewed by personnel from the Multibeam Advisory Committee (MAC), University of Delaware (UDEL), and Reson during sea acceptance trials in October 2012 with satisfactory results and have been used for very high quality mapping exercises (e.g., evaluation of bedform migration at the ‘Redbird Reef’ artificial reef site before and after major storms).

Given the seasonal removal/reinstallation of the Reson 7125, frequent drop keel adjustment (e.g., retracted dockside and extended at sea), and personnel changes since sea trials in 2012, the MAC was asked to review the most recent Reson 7125 installation and perform a patch test prior to the summer 2016 operational season. Preliminary review of the system configuration and functionality testing were performed dockside on March 21 and a patch test was performed during a public day cruise (HRS1602) on March 22 at the ‘Redbird Reef’ artificial reef site. This site was much shallower (20-30 m) than ideal depths for calibration of angular offsets, but included many submerged targets making distinct features for latency, pitch, and yaw calibration, plus ample ‘flat’ seafloor for roll calibration.