Which of the following is considered a navigational aid?

Navigational aids are tools and devices that assist in the process of navigation, helping users determine their position and direction while traveling on water. Buoys and lighthouses are classic examples of navigational aids; they provide visual guidance to help mariners identify safe navigable waters, mark hazards, and indicate the entrance to harbors or channels.

Lighthouses are fixed structures that emit light signals and sometimes sound signals, helping vessels navigate safely during periods of low visibility, such as fog or night time. Buoys are floating devices that mark specific locations and can indicate navigational channels or areas to avoid due to hazards. Both buoys and lighthouses serve crucial functions in maritime navigation by enhancing safety and reducing the risk of accidents.

Radar and sonar, while important in navigation, serve more as technology for detecting objects and mapping the underwater environment rather than direct aids to navigation. GPS systems are navigation devices that provide precise location information but are categorized more as electronic navigation tools rather than traditional navigational aids. Flares and distress signals are safety devices used in emergencies to attract attention but do not assist with navigation in normal circumstances.