The “Crow’s” Nest is an observational Platform placed on a Ship’s Main Mast (mid-way), from which assigned Crewmen would watch for Sailing Hazards or other Shipping. In construction, The “Nest” was made of wood and was squared. Sides extended upwards some 4-feet. Often “Box” shaped, later rounded or semi-rounded shapes were used (known as “Barrel Nest”). This, other than a “Deck Watch” – was (prior to the invention of Radar), the only way a Ship could “see”.
Much debate goes into the origin of the term “Crow’s Nest”. Many tie it directly to early 7th Century Norse Seafarers. Viking mythology is well known for it’s use of The Raven and Crow in their spirituality. It was said that the bird would often soar high among their Ship’s, often roosting on the Mast. Hence a “Crow’s Nest”.
This was considered exceptional “good luck” for a Mission. Yet another Norse “Legend” (sometimes linked to Ancient Rome), states that Ancient Sailor’s kept a small cage with the bird tied to The Main Mast of a Ship. To verify that a land mass was nearby, the bird would be released. It was assumed that the animal would “fly” towards same. Although most Naval Historians cite that the term did not exist until 1807, when The British Navy incorporated it (and the Platform), onto their Warships. Normally, (2) Crewmen were assigned such duties, often lasting 2-hours of Watch. Originally, these men had to rely on their eyesight.
Later, Monoculars (Spy Glass) and Binoculars were used to aid in sighting. Although such Ship Structures are no longer needed by Ships (again thanks to the invention of Radar), some Vessels still incorporate a “Perch” in the unlikely event that a Ship’s Radar fails.