Spotter

A spotter is someone trained to look for something. The term has the following special meanings.

 Weather spotter, an individual who observes the weather to inform other groups. 
 Storm spotter, a weather spotter who observes specific weather events.
 In the military, a spotter is a member of a sniper team.
 In weight training, a spotter will assist someone lifting a weight for safety; see spotting (weight training).
 In bouldering, a person who assists others in accident prevention; see Spotting (climbing)
 In off-roading, a person who assists the driver over obstacles; see Spotting (off-road)
 Transportation enthusiasts who enjoy watching various transport-related activities:
 Train spotter, a railfan.
 An aircraft spotter, someone who engages in aircraft spotting.
 A bus spotter, someone who engages in bus spotting.
 A British term for a police or military intelligence informant.
 Spotter (auto racing), a term used in auto racing
 A local writer for Spotted by Locals