I was thinking of this thread as I was driving to/from Vancouver today driving by locations. If you're headed north from Seattle you'll be on I-5, and it's nowhere near the actual coast. If you do want to explore north of Seattle and are on the I-5 corridor there are a few things:
1) Chuckanut Drive. Very pretty twisty road that's fun to drive. Along the way you can stop at the state park (permit required) and get right down to the water (although it's not the ocean). At the north end of the road you can stop in the Fairhaven neighbourhood of Bellingham which is filled with quaint shops, eating places, etc.
2) Northern State Recreation Area. This is off I-5 in the Sedro-Woolley area.
http://wildliferecreation.org/our-campaigns/wwrp-projects/projects/Northern_State_Recreation_Area will give you directions. It's a bunch of abandoned farm buildings that used to be part of a state mental hospital. Fun to shoot in on sunny days. Not suggested on rainy days, the buildings are leaky.
3) You could take the ferry out to the San Juan islands and drive around. Friday Harbor is nice if you like boats in marinas.
But personally, as mentioned in my prior post, I'd spend the extra time on the WA coast instead
Neil
