What I've never understood is that on the coast the beaches are public and treated as a public highway as far as rules of the road go.
Once you get in Puget Sound they become private.
At the coast you can walk/drive down the public access and then walk up and down the beach as far as you want. Inside Puget Sound, you go to the park and can walk on the beach within it's boundaries.
Never have understood that one. Maybe it goes back to the days before our paved highways when the beach was used.