N.H. Rev. Stat. Ann. § 261:5

The owner of an implement of husbandry or special mobile equipment may apply for and obtain a certificate of title on it. All of the provisions of this subdivision are applicable to a certificate of title so issued, except that a person who receives a transfer of an interest in the vehicle without knowledge of the certificate of title is not prejudiced by reason of the existence of the certificate, and the perfection of a security interest under this chapter is not effective until the lienholder has complied with the provisions of applicable law which otherwise relate to the perfection of security interests in personal property.