33 CFR 62.32: Inland waters obstruction mark.

(a) On inland waters designated by the Commandant as State waters in accordance with § 66.05-5 of this chapter and on non-navigable internal waters of a State which have no defined head of navigation, a buoy showing alternate vertical black and white stripes may be used to indicate to a vessel operator that an obstruction to navigation extends from the nearest shore to the buoy.

(b) The black and white buoy's meaning is “do not pass between the buoy and the shore”. The number of white and black stripes is discretionary, provided that the white stripes are twice the width of the black stripes. Prior to December 31, 2003, this aid shall not be used on a waterway which has a red and white striped obstruction marker defined in § 66.10-15(e)(3) of this chapter, unless all obstruction markers are replaced.