The "vara castellana" is a historical unit of length that was used in Spain. It was commonly used for land measurement and other purposes in various regions of Spain, especially in the Castile region, which is why it is called the "castellana" vara. The exact length of the vara castellana could vary by region and historical period.
In general, the vara castellana was approximately 835.9 millimeters or about 32.91 inches in length. However, variations existed, and in different parts of Spain and at different times in history, the length of the vara castellana could differ slightly.
Like many historical units of measurement, the vara castellana has largely been replaced by more standardized and modern systems of measurement, such as the metric system. In contemporary Spain, the metric system is the standard for length measurement.
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.