What boats are required to be registered?

Vessel registration applies to all vessels except vessels under 16 feet that have no propulsion machinery of any type or vessels that are used on non-federal waters and are 10 hp or less.
Vessels properly registered in another state or country or that have a valid number under federal law and using Washington waters for 60 days or less are also exempt from registration.
Other exemptions may apply. See RCW 88.02.570 (effective July 1, 2011).
Vessel registration applies to all vessels on Coast Guard regulated waters regardless of size. An inflatable raft also must be registered if used on Coast Guard regulated waters and a motor is installed on it.
A vessel can be registered at a local county auditor’s office or any vehicle/vessel subagent location.