VESSELS THAT DO NOT REQUIRE REGISTRATION
Boats registered in another state and not being used in New Jersey for more than 180 days
Boats owned by the United states, a solitary state, a county, or a municipality
Boats registered in another country temporarily plying in New Jersey waters
Racing boats brought into the State for racing or with permit from the New Jersey State Police
A ship's lifeboat
Any boat that is propelled only by oars or paddles, less than 12 feet long
A sailboat without a motor, sailing only on private waters
Surfboards, sailboards, inflatables, canoes and kayaks
http://www.dmv.com/nj/new-jersey/boat-registration