Chapter 2: Q4. (page 55)
Sailors use this method of finding their position when they are navigating near shore, sighting on lighthouses, smokestacks, and other landmarks shown on their charts. They call the small triangle formed by the three sighting lines a "cocked hat," and usually mark their position at the corner closest to the nearest hazard. Why is this a sensible rule?
Short Answer
Itis a sensible rule to sailors as they take positioning from the corner so as to get an accurate fix.