BruceR has a better-reasoned defence of the Canadian submarine program than most I’ve seen - more useful to the average citizen than the 'Real navies have subs. Don't you want a real navy?' line of argument elsewhere.
So what is the point of submarines anyway? Nearly every commentator on the fatal fire on HMCS Chicoutimi has questioned that one, to the point where it seems increasingly likely the major upshot of the tragic death of a naval lieutenant will be the abandonment of any subsurface role by the navy.
Before that happens, it is probably worth pointing out that the four diesel submarines are the only dedicated, full-time maritime sovereignty vessels Canada has left. The only ones. If you're a Canadian hypernationalist, or if you believe Canada should help the United States defend the maritime approaches to the country, they're the only naval resources left you should have the slightest interest in.
rest here.