: I went through all of the loops and finally got the phone number for who to
: call in Washington state.

I was down at my local Licensing office today to renew the tags on my car and I asked about getting a HIN and registration for my tandem (license offices in Washington are privately owned). I said it was a homebuilt kayak with an electric motor. He phoned Olympia and spoke with someone who spoke with his supervisor...

He hung up the phone and said, "How obvious is your motor? Nobody registers kayaks" According to the book I would bring-in reciepts proving I payed sales tax and he could issue a HIN. Then I could get a registration for about $50. I'll probably just take my chances instead.