In a worst case scenario, Sasquatch steals the sails from a 25' Catalina...so you'd be forced to motor (typically a 9.9hp, yes?) from Elliot Bay to Anacortes (inland route). What would be a guestimate for time?
A few years back we brought our son's boat from Shilshole to Anacortes via "the ditch", we left Shilshole around noon, stopped at Edmonds for fuel, and arrived at Anacortes near midnight if I remember correctly. We were surprised to be able to find fuel at that time of night in Anacortes. We were fighting some tide the whole way. This was part of a 31 hour trek Tacoma to Vancouver.
So I'd guess unless you had more favourable tides you're looking at 10-12 hours anyway.
When we brought Oh Joy up to Skyline from Elliot Bay it took us four days. We hit nasty weather all of the way which peaked at 60 knots around sundown the first day. Faced with failing light, a dying GPS and the storm, I thought better of sailing into a strange harbor under those conditions and we diverted to Port Townsend instead. We went back to the boat to finish the trip the following Tuesday. It took us 9 hrs from Elliot Bay to PT the first day. From PT to Skyline in very light air was another 7 hrs..
The fastest I've made it from Shilshoal to Blakely Island (about the same distance as Anacortes) is 9 hours. That was riding a big ebb to Pt. T, and then riding the flood up Rosario (it never quite works just right). It has taken two full days sailing. I think Faster's estimate is about right to go on the inside without much help from currents, depending on motoring speed of your boat.
I could be wrong, but I swear I read somewhere that the bridges over the Swinomish were closed for emergency maintenance right now. Not sure when that started or how long it was supposed to last, but I would check before finalizing your plans... you might not have the option of going up the inside at all.
Fastest I have ever done it is also about nine hours, catching the tides just right. I haven't made that particular trip often enough to give an average, but I go between Shilshole and Port Townsend regularly, and the fastest time has been around five hours and the slowest two days. Wind and weather can cause your trip time to run the gamut, particularly once you hit Admiralty Inlet (nine times out of ten we duck through the Hadlock Canal and avoid that entirely, but it will be further out of the way for you).
Yeah so on a more serious note we went from Seattle to Blaine via Deception Pass and had calms a significant portion of the way, and no motor at the time. The calms were primarily between Skagit Bay and Cherry Pt. I imagine they're worse this time of year than when we went (late March last year).
I would say 12-14 if motoring at hull speed the whole time, using the inside passage part. Took me 10 hrs with a 1 hour stop at LaConner for a late lunch from Edmonds at 6 knots. I doubt a C25 can go 6 knots, probably 5, so even my 12-14 might be on the hopeful side from Seattle proper. That is 2 of not 3 to Edmonds. I can see this being a 2 day trip, or one really long one!