A sounding tube is a section of pipe which runs from the bottom of a tank to a convenient above-tank level. Sounding tubes facilitate the checking of tank levels by sounding rods and allow for the collection of samples of the tanks contents. The sounding tube may be perforated near the top of the tank to provide ventilation while filling. Either integral to the bottom of the sounding tube, or on the bottom plating of the tank, a sounding pad is provided to signal the tank bottom. As sounding tubes are not necessarily straight (particularly in way of forepeak tanks, chain lockers, etc.), sounding tables must take into account the shape of the sounding tube to provide accurate loading information relative to the tanks soundings.