Hand Lead

The hand lead is the 3 to 7 kg sounding weight on a marked lead line, swung by the leadsman in the chains to call depths in shoal water. Markings run by fathom: 2, 3, 5, 7, 10, 13, 15, 17, and 20 fathoms are marked, the unmarked depths called ‘deeps.’ The base is hollowed and armed with tallow to sample the seabed. It predates and backs up the echo sounder, still carried for pilotage and anchoring checks where electronic soundings are doubtful.