Editing Fathom (section)

===Line length===
The components of a commercial fisherman's [[setline]] were measured in fathoms. The rope called a ''groundline'', used to form the main line of a setline, was usually provided in bundles of 300 fathoms. A single {{convert|50|fathom|ft m|adj=on}} [[wikt:skein#en-n-1|skein]] of this rope was referred to as a ''line''. Especially in Pacific coast fisheries the setline was composed of units called ''skates'', each consisting of several hundred fathoms of groundline, with [[wikt:gangion|gangions]] and hooks attached. A ''tuck seine'' or ''tuck net'' about {{cvt|70|fathom|ft m}} long, and very deep in the middle, was used to take fish from a larger [[Seine fishing|seine]].

A ''line'' attached to a [[whaling]] [[harpoon]] was about {{cvt|150|fathom|ft m}}. A ''forerunner'' — a piece of cloth tied on a ship's log line some fathoms from the outboard end — marked the limit of drift line.<ref>{{cite book |last1=Scofield |first1=William Launce |title=Drift and set line fishing gear in California |date=1947 |publisher=California State Printing Office |location=[[Sacramento, California]] |via=[[Calisphere]] |url= http://content.cdlib.org/view?docId=kt5x0nb13m;NAAN=13030&doc.view=frames&chunk.id=d0e245&toc.depth=1&toc.id=d0e245&brand=calisphere |access-date=18 May 2017 |quote=As opposed to drifting, a piece of fishing gear is considered set when it is anchored or attached to the bottom or shore so that it is not free to move about with water or wind currents. By contrast, a drift line or net has no such attachment to the bottom or shore and is therefore free to drift or move with any currents.}}</ref> A ''kite'' was a drag, towed under water at any depth up to about {{cvt|40|fathom|ft m}}, which upon striking bottom, was upset and rose to the surface.

A ''shot'', one of the forged lengths of chain joined by shackles to form an anchor cable, was usually {{cvt|15|fathom|ft m}}.<ref>{{Cite book|title = Dept. of the Army Technical Bulletin TB 43-0144: Painting of Watercraft|publisher = U.S. Government Printing Office|year = 1990|pages = D-2}}</ref>

A ''shackle'', a length of cable or chain equal to {{cvt|12+1/2|fathom|ft m}}.<ref>{{cite book|title=Oxford English Dictionary|url=http://www.oed.com/view/Entry/177171?rskey=dLfO0E&result=1#eid|access-date=23 February 2015|chapter=Shackle n.1, 9.}}</ref> In 1949, the British navy redefined the shackle to be {{cvt|15|fathom|ft m}}.<ref name=Jerrard1986>{{cite book|last1=Jerrard|first1=H. G.|last2=McNeill|first2=D. B.|title=A Dictionary of Scientific Units|date=1986|publisher=Springer Science & Business Media|isbn=9789400941113|url=https://books.google.com/books?id=ApFfBgAAQBAJ&q=shackle+unit+of+length&pg=PT198|access-date=3 March 2015}}</ref>

The [[Finland|Finnish]] fathom (''syli'') is occasionally used: {{frac|1000}} [[nautical mile]] or {{frac|100}} [[cable length]].