rjs (Ray) ...Good question.
When I brought in the USA boat & USA trailer ya just go into the Canada Customs. Show them the paper-work.
They will take it from there ...it took about 10 minutes after getting to the customs worker.
As far as transporting the trailer & boat (insurance) from the border to your home...well I was give 2-3 stories...
They told me that I could go to the truck weigh scale (1/2 mile down the road from the Douglas crossing) & they could get me a permit.
Well when I went in to get it the guy just told me that my veicle's insurance will cover the boat trailer TILL I got the boat & trailer to my house.
That's what I was told. ( so I just drove home)
But now to get the boat trailer checked at the Canadian Tire (a few days after getting the boat home) ya just go to your ICBC agent & they will give ya a day's insurance ...something like $25 or $35 dollars.
After Canadian Tire checks your trailer they will send the info to "forgot the name"...anyways within a few wks you will get a letter in the mail & with the letter you then can go to the ICBC & get your BC trailer plate & insurance.
Before taking the trailer on the road make sure the brake & signal lights are working & it is safe to travel on the highway.