Documents seen by the Ottawa Citizen under Freedom of Information requests show only one of four secondhand diesel submarines purchased from Britain for nearly $900 million 10 years ago by a previous Liberal government is seaworthy.

A briefing note prepared for Defense Minister Peter MacKay seen by the newspaper advised him to play down the series of setbacks in refitting the Victoria-class subs, and rather focus on the "important strategic" value they play.

Repairs and upgrades to the three mothballed subs have a time line of one coming on line by 2009, and a final date of 2012 for the other two, the report said.

One of the subs caught fire off the coast of Ireland in October 2004 on its maiden voyage from Scotland to Halifax, Nova Scotia, and a Canadian sailor was killed and eight other injured.