The conclusion was made in a report to Parliament by Auditor General of Canada Michael Ferguson.
"The air force and the coast guard's ability to respond to incidents has been a testament to the dedication of search-and-rescue crews," he said. "(But) we are very concerned about the sustainability of search-and rescue services in coming years."
SAR operations, managed mainly by the two services, are being affected by personnel shortages in the air force and difficulties in recruiting and training difficulties, the report said.
Also affecting current and future operations is the Air Force's use of older fixed-wing aircraft that require "extensive" maintenance and older helicopters.
"In addition, the information management system used to manage search-and-rescue cases is nearing its breaking point," the Auditor General's office said. A replacement system is not expected until 2015-16."