Sounding rod

(Naut.) a rod used to ascertain the depth of water in a ship's hold.

See also: Sounding

References in periodicals archive ?
Fishermen capture these intelligent marine mammals by working in small boats, using sounding rods below the water's surface to interfere with the dolphin's sonar and navigational abilities.
The most advanced acoustic monitoring systems use solid metal "metalborne" waveguides, or sounding rods, which are spot-welded to various locations on the boiler's casings and tube membranes.