And some more insight:
Like Tracker said, day trips into Canadian waters are not a problem. You still need a Canadian license. The fines are very steep by US standards if you're caught fishing in their waters without one. Even if you have a Canadian fishing licence, Canadian caught/tagged salmon must be of legal size, species and limits for the WA port you return to like Port Angeles.

Oh, but there's more...the ONLY exception is if you obtain a Canadian customs clearance certificate (i.e. stay the night night in Canada), then you can bring back Canadian limits which is 4 per day or 8 in possession. There's some gray area with this too...what I'm not real clear on is whether the WA port has to be open for salmon before bringing Canuck salmon to the dock? The answer seems to be muddled in the regs.
It's all mute if your not checked by WDFW, but could be some costly fish if not in compliance when you are.
PM'd you my phone number to discuss further.