Abstract Extensive airborne electromagnetic (EM) ice thickness surveys have beenperformed in April 2009, 2011, and 2012 over the Canadian Beaufort Sea with along-range airplane. These are contributing to the Beaufort RegionalEnvironmental Assessment (BREA) project which gathers ice information inpreparation of a regulatory framework for safe and environmental responsibleoil and gas production. Results show that the location of the multiyear iceedge can be very variable from year to year. Multiyear ice modal thicknessesranged between 3.0 and 3.7 m. The seasonal ice zone had very variable icethicknesses depending on the amount and age of ice formed in coastal polynyasand leads throughout the winter. However, we gathered enough data to show thatmodal first-year ice thicknesses of 2.0 to 2.2 m emerge if profiles are longenough, which can be considered the most representative first-year icethickness estimate in the Canadian Beaufort Sea in April. However, in theseasonal ice zone also regions with heavily deformed ice thicker than 10 m, andoccasional multiyear hummock fields of similar thicknesses occur. Resultssuggest that multiyear hummock fields may not comprise the thickest ice as theyare affected by melt during the summer. Two ice islands had thicknesses between20 and 30 m. Our results suggest a melt rate of ice islands of 10 m per year inthe Southern Beaufort Sea. Ice thickness surveys were complemented by theanalysis of satellite radar data and tracking of ice features by means of GPSbeacons. We demonstrate that all these activities combined comprise a powerfultool for a future Arctic sea ice environmental observatory.