vessel
Vessel of the United States or U.S. vessel means: (1) Any vessel documented under chapter 121 of title 46, United States Code; (2) Any vessel numbered under chapter 123 of title 46, United States Code, and measuring less than 5 net tons; (3) Any vessel numbered under chapter 123 of title 46, United States Code, and used exclusively for pleasure; or (4) Any vessel not equipped with propulsion machinery of any kind and used exclusively for pleasure.