Beacon: any fixed lighted or unlighted daymark.
Breakwater: an offshore structure used to protect a harbor or beach from the force of the waves.
Catwalk: an narrow elevated walkway, allowing the keeper access to light towers built out in the water.
Crib: any light structure that sits out in the water away from the beach or pier.
Daymark: unique color, pattern or architecture of towers and other markers used by navigators to mark their location during the day.
Gallery: outdoor railed walkway encircling the watch room where the keeper sat and monitored the lantern and weather conditions.
Pier: a structure extending into navigable waters for use as a landing place, or to protect or form a harbor.
Range lights: used by mariners to fix their position in open water and guide them into port. Range lights usually appear in pairs and are 1000 feet apart.
Shoal: a shallow area, such as a sandbar or rock formation.
Tower: a raised skeletal or walled structure with a light signal devise at the top.
Reprinted with permission from the 1993 Educational Resource Guide, Great Lakes Lighthouse Keepers Association. (313-436-9150).