Why didn't the defence department buy these subs?

  HMCS Corner Brook, one of the four used British submarines Canada bought in 1998.

1 0f 4 West Edmonton Mall Subs The submarines each weigh about 38 tonnes and are made from lead and aluminum, which will be sold for scrap metal.

Wednesday, March 21, 2012, Paying Attention - Paul Willcocks Blog

West Edmonton Mall is selling its fleet of submarines, an opportunity that the Canadian Navy has somehow failed to seize. After all, the four submarines are cheaper than the British castoffs the navy bought, which have provided total failures.  And they apparently work. Unlike the British subs.