One of Canada's submarines is returning to port due to a mechanical problem with one of its diesel engines.
The navy says HMCS Windsor was training off Canada's east coast Friday when the problem was detected.
The sub has backup systems, but the navy says it decided it would be prudent to return to Halifax where a thorough inspection can be done.
It's been a busy year for the Windsor -- the navy says the sub has been at sea for 200 days over the past year conducting a variety of duties.
The Windsor is one of the four submarines that Canada bought from Britain in the late 90s, but the vessels have been plagued with various mechanical problems.
A fire on board Windsor's sister HMCS Chicoutimi in 2004 killed one crew member and all four subs have spent lengthy periods in drydock.
Source: CTV News