Cruise ID: RR2401 Multibeam System: EM712/EM124 Dates: February 12, 2024 During the winter 2023-24 maintenance period, the R/V Roger Revelle (RR) underwent significant engine work and received a new Seapath 380 receiver and HMI (the MRU 5+ and antennas were not modified) The Multibeam Advisory Committee (MAC) was asked to assist with routine Quality Assurance Testing (QAT) for the ship’s multibeam echosounders; due to scheduling conflicts, the MAC provided remote support for planning and data analysis leading up to and throughout the QAT Planning followed the standard MAC SAT/QAT checklist, starting with configuration review, hardware health, and noise testing following the engine work; calibrations for both systems were carried out at proven sites near San Diego used by a variety of vessels (e.g., 2023 Sally Ride EM124 and EM712 QAT) Dockside configuration reviews indicated a rollback to outdated offsets for the EM124 (e.g., potentially by loading an older PU parameters

Cruise ID: RR2301 Multibeam System: EM124/EM712 Dates: February 4-19, 2023 R/V Roger Revelle (RR) underwent routine calibrations of the ship’s multibeam echosounders during an extended transit/cruise between Punta Arenas, Chile, and Cape Town, South Africa in February 2023; the MAC provided remote support for planning and data analysis leading up to and throughout the calibration Planning followed the standard MAC SAT/QAT checklist, focusing on calibrations at suitable sites within reasonable deviations along the transit route; these were completed in two phases with initial EM124 testing near Puntarenas, followed by EM124 re-calibration and EM712 calibration at suitable sites off Cape Town The initial EM124 calibration was completed with a TX array pitch error inadvertently held over from the 2020 EM124 and EM712 SAT; this was corrected for the second calibration, resulting in typically small adjustments During the approach to the second calibration area off Cape Town, an EM712 configuration error was

Cruise ID: RR1301 Multibeam System: EM124/Seapath 380 Dates: January 21-23, 2013 The accuracy (repeatability, strictly speaking) analysis indicates that the system is performing within expected levels.