Sign at CFS Alert. During April-May 2015 at CFS Alert, personnel from Defence Research and Development Canada (DRDC) test the performance of new and existing models of the icepick geobuoy in the Arctic environment. The icepick geobuoy was developed for the Royal Canadian Air Force (RCAF) to allow for the passive acoustic tracking of marine traffic operating beneath Arctic ice, and is deployed from a CP-140 Aurora aircraft.