This is true, and I did it for a couple of years in the Great Lakes. The import date to Canada that starts the 12 month calendar is the entry date for you and the boat as documented by your customs clearance. In any case since you don't check out of Canada, they have no way of knowing when you did, other that the US customs check in date (which they may well have access too - don't know).All you need to do is take the boat out of Canada. So go to WA or AK for a bit, then return to Canada. I have heard that simply checking into the US at one of the San Juan arrival points is sufficient, and you can immediately return to Canada.
Checking in to Canada is usually very easy, a phone call from a listed port of entry (and there are many). Only once in scores of entries was I asked to wait, they came and gave the boat a thorough search (this was in the year following the Covid closures) then said have a nice trip. Usually you receive the clearance number on the phone.
This is what the statue says, in plain language. 60 days "in the Waters of the State of Washington". It is cumulative, that is the 60 days need not be contiguous. This is a main reason for all the dry storage yards in Anacortes. So an alternative to leaving the boat in Canada (for a commuter cruiser) is to leave it in dry storage in Anacortes, and make sure that from the time it is dropped in the water until you leave WA, and the time in the water in WA until hauled again, is less than 60 days in 365. You do not owe WA taxes in this case.Until the DOCUMENTED boat is “in the water for greater than 60 days”, or “WA becomes the principal place of use”, the documented vessel can remain registered in another (cheaper) state and not be registered in WA. Colorado charged about $100 a year to register. I called the WA officials and they had me on a prolonged hold while they researched this. Finally, they came back to say that as long as the boat was not in the water for more than 60 days a year, the arrangement was legitimate.
Leaving it in Canada, you can also opt for dry storage, cheaper than wet and fewer worries. VanIsle Marina has a really great facility for this - it is what I did for 8 years leaving a boat in Canada and would do again. But you still have a 12 month rule. I was caught by that during Covid, I was not allowed to visit the boat for over 18 months. I did not get a tax bill, but worried about it.