That's the line I came up with too. I'm pretty sure it launched from Skagit Bay or Saratoga passage south of Whidbey NAS. Skagit Bay gets relatively shallower towards the NAS so I think Saratoga Passage between Oak Harbor and Coupeville is the best bet. Plenty deep there and just aways from Bangor. They're supposed to go in and out of the Sound on the surface but I know they move around the Sound submerged too. The Island is heavily forested so many wouldn't see it even if they were awake and there was a very small window of time it was visible. I don't see how it could be anything other than a missle from a submerged launch. If it looks like a missile and flies like one it probably is one. I concur it probably wasn't a Trident although that's just a guess on my part.