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.
"Aln" is a unit of length that is used in some parts of Scandinavia, particularly in Sweden and Norway. The term "aln" is derived from the Old Norse word "alinn," which means "forearm." Historically, it was a common unit of measurement for cloth, textiles, and land.
The exact length of an aln could vary by region, but it was generally around 2 Swedish feet or approximately 59.4 centimeters (or about 23.4 inches) in Sweden. In Norway, an aln was somewhat longer, typically around 62.7 centimeters (about 24.7 inches).
The use of the aln as a standard unit of measurement has largely been replaced by the metric system in Scandinavia and most parts of the world, but it may still be referenced in historical or traditional contexts.