Seattle Municipal Code § 7.20.110

owner
occupies or reoccupies a floating home which has been rented, or when a renter of
a floating home becomes its owner through purchase or otherwise, the moorage fee shall,
as of the date of such occupancy or purchase, be set at the rate established for other
comparably situated owner-occupied floating homes at the same moorage site, consistent
with Sections 7.20.080 and 7.20.090 of this chapter.