Navigation lights can help to prevent collisions by making the vessel and its direction of travel more evident to operators of other vessels. From the information provided by navigation lights, one can deduce the direction of travel of other vessels and whether they are at anchor or engaged in some other activity. Vessels in vicinity will make collision avoidance decisions based on the information your lights provide. The collision regulations require navigation lights to be shown from sunset to sunrise and during periods of reduced visibility. It is important to ensure that a vessel is equipped with the required lights of the right intensity and that they are correctly mounted. Proof is required that navigation lights comply with the requirements of the Collision Regulations The rules that apply to a vessel depend on its length, type of propulsion, and the waters in which it is operating.