§ 638. Coast Guard ensigns and pennants

(a) Coast Guard vessels and aircraft shall be distinguished from other vessels and aircraft by an ensign, pennant, or other identifying insignia of such design as prescribed by the Secretary. Such ensign, pennant, or other identifying insignia shall be displayed in accordance with regulations prescribed by the Secretary.
(b) No vessel or aircraft without authority shall carry, hoist, or display any ensign, pennant, or other identifying insignia prescribed for, or intended to resemble, any ensign, pennant, or other identifying insignia prescribed for Coast Guard vessels or aircraft. Every person violating this subsection shall be fined not more than $5,000, or imprisoned for not more than two years, or both.