fish4steel your reading it wrong again.

basically your only safe bet is to pay the $11.50 and get some numbers. The only places you don't need a registered boat to run a motor. you most likely won't need a motor there anyway.

* No, if 10 horsepower or less when used only on non federally regulated waters.
(Federal waters, where registration is required on all mechanically propelled vessels regardless of size (gas, diesel, electric), include Puget Sound, Hood Canal, Lake Washington, Lake Union, Lake
Sammamish, Columbia River, Snake River, Lake Washington Ship Canal, Capitol Lake, Pend Oreille River, Walla Walla River, Yakima River, and other bodies of water effected by the ebb and flow of the
tide and are on or bordering federal land. For further clarification of federal waters, please contact the local marine law enforcement office in the jurisdiction.) Exception: Vessels equipped with propulsion
machinery of less than ten horsepower that: (a) Are owned by the owner of a vessel for which a valid vessel number has been issued; (b) Display the number of that numbered vessel followed by the suffix
"1" in the manner prescribed by the department; and (c) Are used as a tender for direct transportation between that vessel and the shore and for no other purpose are not required to be registered.