Origin of the Fathom
 

I was wondering the other day where the measurement of a Fathom came from when I got a flash. 6 feet is just about what you get when you coil a rope at full arms length allowing for a slight slack in the rope. Is this where it came from? Coiling up a leadline and counting the number of coils of rope? If I am full of it where did the measurement come from?

Spot on. If you google to on-line etymology you get:

fathom (n.) O.E. fæðm "length of the outstretched arm" (a measure of about six feet), also "arms, grasp," and, figuratively "power," from P.Gmc. *fathmaz "embrace" (cf. O.N. faðmr "embrace, bosom," O.S. fathmos "the outstretched arms," Du. vadem "a measure of six feet"), from PIE *pot-/*pet- denoting "stretching out" (cf. Gk. petalon "leaf," L. patere "to be open"). The v. meaning of "take soundings" is 1607; its figurative sense of "get to the bottom of, understand" is 1625.

G’luck

Ian McColgin
S.V. Marmalade