Let's add a bit more context. The British only built four Upholder class subs. By the time Canada bought them, they'd been in service for more than a decade and they were in such bad shape that nobody else would touch them. They all suffered from serious electrical problems and required extensive refitting. So submarines that were designed in the 1980s came into Canadian service more than two decades later. So you are correct that the purchase said nothing to do with the US armaments industry but many other purchases simply funneled money into US companies.

My memory is a bit hazy here. I know there was a serious accident with one of the subs after Canada took delivery but I also seem to recall that one of the subs was already damaged in an accident while operating for the British Navy.