14 C.F.R. § 25.1399 Riding light.
Title 14 - Aeronautics and Space
(a) Each riding (anchor) light required for a seaplane or amphibian must be installed so that it can— (1) Show a white light for at least 2 nautical miles at night under clear atmospheric conditions; and (2) Show the maximum unbroken light practicable when the airplane is moored or drifting on the water. (b) Externally hung lights may be used.
Title 14: Aeronautics and Space
PART 25—AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY AIRPLANES
Subpart F—Equipment
Lights
§ 25.1399 Riding light.
