A fathom is a unit of length used primarily to measure the depth of water. It is exactly equal to 6 feet, or approximately 1.8288 meters
. The term originates from the Old English word faedm meaning "outstretched arms," reflecting the original measurement as the distance between the fingertips of a man's outstretched arms
. Historically, sailors measured depth by lowering a weighted line marked in fathoms into the water until it touched the bottom, then counting how many fathoms of line were let out
. Although modern electronic depth measurement tools have largely replaced this method, fathoms remain a traditional unit in nautical contexts and on some older or specialized charts
. In summary:
- 1 fathom = 6 feet (1.8288 meters)
- Used mainly for measuring water depth
- Originated from the span of a man's outstretched arms
