RE: Fuel docks - Anacortes, Bellingham, & vicinity
I've found that Cap Sante fuel dock is one of the higher priced places around. I generally bought fuel in LaConner for my gas boats. They were sometimes as much as 25 cents cheaper. A phone call would be worth the effort.
When you cross over into the islands the price of fuel continues to rise quickly and if you want the ultimate shock, pull in to Friday Harbor and buy fuel. Years ago the fuel dock help wore t-shirts with some witty saying, the gist of which was, "we have the highest priced fuel and we're proud of it". I think even Roche Harbor was cheaper at the time.
No idea of where you might be cruising, but Brownsville and Poulsbo, down south of Anacortes, trade off being reasonable also. Edmonds used to be, but they seem to have decided to remodel their facilities with fuel profits.