Section 30.57 - Perfection of security interests(1) Except as provided in sub. (2), a security interest in a boat of a type for which a certificate of title is required is not valid against creditors of the owner or subsequent transferees or secured parties of the boat unless perfected as provided in this section and ss. 30.572 and 30.573.(2) Sections 30.57 to 30.576 do not apply to any of the following:(a) A lien given by statute to a supplier of services or materials for a boat.(b) A lien given by statute to the United States, this state or a political subdivision of this state.(c) A security interest governed by ch. 409 that is created by a manufacturer or dealer who holds the boat for sale.(3) Except as provided in sub. (4), a security interest is perfected by the delivery to the department of the existing certificate of title, if any, an application for a certificate of title containing the name and address of the secured party, and the required fee. The security interest is perfected as of the later of the time of its delivery or the time of the attachment of the security interest.(4) If a secured party whose name and address is contained on the certificate of title for a boat acquires a new or additional security interest in the boat, the new or additional security interest is perfected at the time of its attachment under s. 409.203.(5) An unperfected security interest is subordinate to the rights of persons described in s. 409.317.(6) The rules of priority stated in s. 409.322, the other sections referred to in that section, and subch. III of ch. 409 shall, to the extent appropriate, apply to conflicting security interests in a boat of a type for which a certificate of title is required.(7) The rules stated in subch. VI of ch. 409 governing the rights and duties of secured parties and debtors and the requirements for, and effect of, disposition of a boat by a secured party, upon default shall, to the extent appropriate, govern the rights of secured parties and owners with respect to security interests in boats perfected under this section and ss. 30.572 and 30.573.(8) If a boat is subject to a security interest when brought into this state, s. 409.316 states the rules which determine the validity and perfection of the security interest in this state.