Feet to Fathoms Converter

To convert feet to fathoms, follow these steps:

1. 1
   Enter the value in feet
2. 2
   Click "Convert to Fathoms"
3. 3
   View the result in fathoms

What is a Fathom?

A fathom is a unit of length in the imperial and U.S. customary systems used primarily for measuring water depth. One fathom is equal to 6 feet or 1.8288 meters exactly. The term "fathom" comes from the Old English word "fæðm," meaning "embracing arms" or "outstretched arms," referring to the distance between a person's fingertips when their arms are stretched out to the sides.

Historical Significance

The fathom has been used as a maritime unit of depth measurement since ancient times. It was a practical unit for sailors because they could quickly estimate a fathom by extending their arms. In early navigation and seafaring, this human-scale measurement allowed mariners to determine depths without specialized equipment.

The Ancient Greeks had a similar measurement called the "orguia," which was also based on the span of outstretched arms. By the Byzantine period, this had evolved into two forms: a standard orguia (about 6 feet) and an "imperial" orguia that was slightly longer.

Maritime Applications

Fathoms have been integral to maritime navigation for centuries, particularly for:

• Depth Sounding:Traditionally, sailors would use a weighted line marked in fathom intervals (known as a sounding line) to determine water depth. They would lower the line until it touched bottom, then count the number of fathoms by the markings on the line.
• Nautical Charts:Before the widespread adoption of metric systems, nautical charts indicated depths in fathoms. In fact, many nautical charts produced by the U.S. Hydrographic Office still use fathoms and feet.
• Safe Navigation:Knowing the water depth in fathoms is crucial for ensuring safe passage of vessels and avoiding underwater hazards.
• Anchor Rode Measurement:Sailors often measure anchor line (rode) in fathoms to determine the appropriate scope (ratio of line length to water depth) for secure anchoring.

Different Types of Fathoms

Throughout history, there have been several variations of the fathom:

• International Fathom:Exactly 6 feet (1.8288 meters)
• British Admiralty Fathom:Originally defined as 1/1000 of a nautical mile, which was about 6.08 feet
• Warship Fathom:Exactly 6 feet, used historically by British and American navies
• Merchant Vessel Fathom:Historically varied between 5 and 5.5 feet in England until the 19th century

Fathoms in Literature and Culture

The fathom has also made its way into literature and popular culture:

• Shakespeare's "The Tempest" includes the famous line, "Full fathom five thy father lies," referring to a drowning at a depth of five fathoms.
• The phrase "to deep six something" (meaning to dispose of or discard something) originates from maritime burial practices, which traditionally required at least six fathoms of water.
• Mark Twain's pen name comes from the term "mark twain," which riverboat crews would call out when the water depth measured two fathoms (12 feet), indicating safe passage.

Modern Usage

While the metric system has become the international standard for most measurements, fathoms are still used in several contexts:

• U.S. navigational charts still commonly use fathoms for deeper waters (typically depths greater than 30 feet)
• Traditional fishermen and mariners, particularly in the United States and United Kingdom, continue to use fathoms
• Diving communities sometimes reference depths in fathoms
• In cable and anchor chain measurements, where units like "shots" (15 fathoms or 90 feet) and "shackles" (12.5 or 15 fathoms) are derived from the fathom

Related Nautical Measurements

Several other nautical measurements are related to or derived from the fathom:

• Cable Length:Historically 100 or 120 fathoms, depending on the navy
• Shot:A length of anchor chain equal to 15 fathoms (90 feet)
• Shackle:A length of cable or chain equal to 12.5 fathoms (75 feet) traditionally, though redefined by the British Navy in 1949 to be 15 fathoms

Fathom Conversion Table