lead line

English Thesaurus

1. (nautical) plumb line for determining depth (noun.artifact)

hypernym	:	perpendicular, plumb line,
definition	:	a cord from which a metal weight is suspended pointing directly to the earth's center of gravity; used to determine the vertical from a given point (noun.artifact)

part holonym	:	sounding lead,
definition	:	a metal bob at the end of a sounding line (noun.artifact)

domain category	:	navigation, sailing, seafaring,
definition	:	the work of a sailor (noun.act)