I don't think there is a source for free Canadian navigational charts online. It took awhile for the US government to become enlightened enough to stop their previous practice of only allowing the maps to be re-sold via 3rd party retailers. It looks like the Canadian gov't hasn't caught up on this issue yet. You can buy digital downloads of Canadian navigational charts in raster format from here.
I have looked for cheap or even reasonably priced Canadian charts for years and come up empty
I wouldn't trust it as a primary navigation source but 'Navionics' sells an iPod/iPad application for under $10 that includes all of the charts for the west coast.
I am embarrassed to admit that I have fallen back on this more than once after forgetting the real charts at home.
We haven't made the C-Dory jump yet so I am still traveling at 5knots which gives me lots of time to fiddle with the silly little computer.
I ordered direct from Fugawi and regretted it. The shipping took forever (three weeks) and then I got a bill for customs duty. I paid the same price as if I had bought in the USA.