leadsman

Etymology 1

From Middle English ledes-man (“a military commander”, “a general”); equivalent to leads (the genitive form of lead: “a leading”, “a directing”, “a guiding”) + man.

noun

1. (obsolete) lodesman (a leader or guide)

Etymology 2

From (genitive form of) lead (“heavy metal; Pb”) + man.

noun

1. (nautical) A sailor who takes soundings with a lead, measuring the depth of water.
   In the same moment the leadsman hove the lead, and, finding it directly take the ground, he, in his fright, called out, ‘There's only three fathom.’ 1808–10, William Hickey, Memoirs of a Georgian Rake, Folio Society 1995, p. 205