I am a Canadian, I kept my boat in PT Roberts. In
Washington. It is state registered in
Oregon.
Sailing from
Oregon to Washington. or back No problem, I cross the border, I answer US Border guards questions.
Where you going. To the marina going sailing, Response have a nice day. Enjoy your trip.
My mum is British, She comes to Visit. We go down to Pt Roberts.
No problem. She has to go into office and fill out a card for 6 months as a visitor to US, after we go back and forth.
Border Guard waves ask how my mum is doing is she enjoying her holiday.
We can sail all the way down the coast to Oregon or even
California.
We can cross by boat in to
Canada and back into Washington we have to go to Port of Entry. No problem.
I asked, All no problem so long as I do not leave US waters after entry.
To get to Hawwii I would have to leave US waters and cross international waters before returning to US waters.
I can do it in an airplane from Seattle or Belingham.
They have different rules for
Planes, trains automobiles and boats.
I was told I would have to Leave US and re-enter US in Hawaii.
As a Canadian it would not be a problem.
My mum being British does not need a visa to enter us by plane or car and
provided she has the 6 month card it was ok to enter by boat.
Sorry not a complete answer, Its a bit complicated and I would advise She has a chat with US Border and tells them exactly what her plans are.
They will probably give her the same card which will allow her to make entry into US by land or boat for 6 months.
As a Canadian. I can't own a US registered boat. I can own A state registered boat. No special permit just the same Green Washington State permit on the bow, All boats resident in Washington, I got it along with my Marina Fee.