That’s a U.S. Coast Guard file photo of the Eagle, a tall ship the USCG uses for training. It’s on the way to visit the USCG station on the downtown waterfront, so you’ll see it in Elliott Bay later today (we just checked Vessel Finder, and it’s in the North Sound, about to turn southward along Whidbey Island, traveling at 11 knots right now so likely a few hours out).
P.S. Checking the WSB archives, we covered a visit by the Eagle in 2008.