Fathom

Kayakers usually encounter fathoms in the context of navigation. Fathoms are used to measure water depth on some charts; in this useage a fathom is exactly six feet.

In a more general context, a fathom is the distance from one outspread fingertip to the same finger tip of the other hand when the arms are held as far apart as possible on either side of the body. This distance is normally very close to the individual's height. A fathom for the purpose of SOF kayak building is different for each individual.