In the United States surveying system, a "link" is a unit of length that is equal to 1/100th of a chain. Each link is approximately 7.92 inches long or about 0.201168 meters. This unit is primarily used in surveying and land measurement in the United States.
Surveyors often use a chain, which is comprised of 100 links, to measure distances in land surveys. The use of links and chains allows for precise measurements of land parcels, boundaries, and property lines.
A fathom is a unit of length used to measure the depth of water or the depth of objects underwater. In the international nautical mile system, one fathom is equal to exactly 1.8288 meters or approximately 6 feet. However, in the United States, the customary value for a fathom is often rounded to 6 feet.
Fathoms are commonly used in navigation, maritime activities, and underwater exploration to measure the depth of bodies of water, the draft of ships, and the depth of diving. Sailors, fishermen, and divers often use this unit to assess water depths.