Cruise ID: HLY24TE Multibeam System: EM122 Dates: August 13-14, 2024 Elevated sea state and corresponding bubble sweepdown issues severely impacted data quality during the initial calibration attempt on June 20; a second, successful attempt was carried out in calm water on Aug 13, 2024 The USCGC Healy (HLY) is equipped with a Kongsberg Maritime EM122 multibeam echosounder (1° TX x 2° RX) with Seapath 330+ (primary) and Applanix Oceanmaster POS MV (secondary) navigation systems The Multibeam Advisory Committee (MAC) was asked to assist with Quality Assurance Testing (QAT) of the ship’s multibeam echosounder ahead of the 2024 field season; due to scheduling constraints, MAC personnel provided remote support for line planning and data analysis MAC communication with Healy and UCSD/STARC personnel (primarily Emily Shimada, Max Hughes, and Brendon Mendenhall) commenced in May 2024 with planning to effectively repeat the 2020-23 QATs off the coast of Washington, including: • calibrations (‘patch