The salmon (and winter time steelhead) cruise along the shore within 50 feet on Bush Point near Freeland on Whidbey, best month for coho being October with some bruiser chum mixed in. It may not be open to keep salmon most years, but when it's open for angling the fishing can be incredible.
Point no Point is also productive, as these guys will attest. The south end near Defiance and the Narrows is another spot where you will score.
There are miles of unexplored shoreline on the straits... I think the coastal salmon FF scene will blossom over the next decade, if we can keep the runs in good health.