leadsman
Nautical depth checker
A leadsman is a sailor who measures water depth by casting a sounding lead—a weighted line marked at intervals.
Standing at the bow, the leadsman would call out depths to help navigate shallow waters: The leadsman sang out "by the mark, twain"—two fathoms.
The role became obsolete with electronic depth finders.
Tool indicating true vertical
- fathomNautical depth unit
- soundingsMeasured water depths
- castPerformers, throw, or splint
- bottomLowest point or underside
depths · measure · plummet · survey · seabed · echo · probe · tallow
plumbline
Tool indicating true vertical
bottom · depths · measure · plummet · survey · seabed · echo · probe · tallow · arming
helmsman
One who navigates vessels
quartermaster · boatswain · coxswain · deckhand · shipmate · seaman · forecastle · lookout · mate · captain
channel
Passage for transmission
pilotage · harbor · berth · draft · clearance · passage · chart · course · bearing · heading