N.H. Rev. Stat. § 270-A:2
A houseboat may be beached or grounded, or tied to the shore of any of the inland surface waters of the state for an overnight period, or any part of an overnight period, only when on or at a location owned, leased, or otherwise under the control of the owner or operator of the houseboat or by permission of the owner, lessee, or person otherwise in control of such location. An unoccupied houseboat may be anchored on the inland surface waters of the state for an overnight period, or any part of an overnight period, only in an area reasonably adjacent to a location owned, leased, or otherwise under the control of the owner or operator of the houseboat or by permission of the owner, lessee, or person otherwise in control of such location.
RSA 270-A:2
1967, 412:1, eff. Jan. 1, 1968.