CROW is a project carried out mainly by Canadian rangers as part of their regular activities for DND. Initially, simple but key observational parameters will be measured: snow and ice thickness; snow/ice interface temperature; and in the sea water: temperature, salinity, chlorophyll content, and dissolved oxygen. These quantities will be measured at flexibly determined locations by Canadian Rangers on snowmobiles near the villages of Kugluktuk, Cambridge Bay, and Gjoa Haven on patrols during the ice-covered period. Water properties will be profiled using an internally recording instrument. Profiles will help in understanding circulation and changes in the ocean. At a subset of the above science stations, an ice buoy will be deployed and left frozen in the ice to measure ice and water temperatures at hourly intervals, and transmit this data real-time via an Iridium link. The data will be used to help predict ice break up in the area.