When you bring the boat up to Maine you go into the town office and pay the excise tax and the 5% sales tax. You can probably get away with waiting until yu have the new documant to pay the excise and sales tax. The town office there in Belfast will know what to do. Make sure you get a receipt for the sales tax because once the boat shows up on the documentation rolls the state will likely send you a letter demanding proof that you have paid the sales tax.