How far can you see at sea? Because of the curvature of the planet and the sea as a relatively flat surface the rule is 1.17 nautical miles times the square root of the height in feet of the object you are looking for. So in perfect weather with no clouds an Island that was 1000 feet above sea level would be first visible from about 37 miles out at sea. A ship with a mast at 20 feet would be first visible at 5.23 miles with the tip of the mast showing first ,then the sails followed by the hull of the ship. If the hull was only 6 feet above the water then the ship would be 2.8 miles away before the hull could be seen. A person clinging to wood with just their head out of the water could not be seen until they were about 1 mile away. A farsee magnifies what can be seen, so a 20X farsee makes objects at a distance of 20 feet look like they are only 1 foot away. However the fare see can't make an object that is beyond the curvature of the planet be seen, until the object is visible above the horizon. Then the use of the farsee can magnify details.
|
|