HMCS Chicoutimi is conducting controlled dives in waters near Victoria, submerging for the first time since an extensive refit was ordered after a deadly fire.
Captain Jamie Clarke, Director of the Canadian Submarine Force for the Department of National Defence says the Chicoutimi's return would give Canada's navy three submarines for use.
The latest dive to ensure Chicoutimi is water tight is just the start of a rigorous series of sea trials necessary before the Victoria class sub is fully operational.
It has been sidelined since a flooding incident led to an electrical fire that killed one sailor and injured two others in 2004.
The blaze occurred as Chicoutimi was on its first voyage to Canada, after being purchased from the United Kingdom, which had retired the sub almost 10 years earlier. (CFAX)