Under a chattel mortgage, your lender agrees to purchase the boat, and you agree to make regular repayments. The lender registers a mortgage on the boat, with interest rates fixed for the life of the loan. The advantage of this loan for small business is that if the boat is used for business purposes, interest charges and depreciation may be tax deductible.
If you want a straightforward loan with the stability of your repayment amounts and interest rate fixed over the life of the loan, you can take out a secured loan. This means your boat will be used as security (guarantee) against the loan. So if for any reason you are unable to pay off your loan, your boat will be sold and used to reducing the remaining loan amount. Any unpaid balance will be your responsibility.