The R/V Kilo Moana undertook an engineering shakedown leg (KM1505) in order to perform geometric calibrations (‘patch tests’), swath coverage assessments, and data quality evaluations for the vessel’s Kongsberg Maritime EM122 and EM710 multibeam echosounders. Data were collected southwest of Honolulu during April 28-29, 2015 (Figure 1). Paul Johnson and Kevin Jerram provided logistical and technical support for mission planning, data collection, and analysis. Most tasks planned for the EM710 were completed, whereas poor data quality for the EM122 precluded further testing and curtailed operations a day early. These issues are presently under review by Kongsberg Maritime, Gates Acoustic
Services, the Ocean Technology Group at the University of Hawaii at Manoa, and the Multibeam Advisory Committee. This report presents:

1. a history of documented changes to system geometry for the EM710 and EM122, including modifications made during KM1505;
2. an overview of the data collected and the processing methods applied;
3. results of the geometric calibration (‘patch test’) for the EM710;
4. swath coverage / extinction data for both the EM122 and EM710;
5. vessel self noise as measured by the EM122 multibeam receiver at various speeds; and
6. EM122 transducer impedance data to document transducer health.