depth finder; sounder; bathymeter
Technical term for a device that measures water depth, used in marine surveying and navigation.
We surveyed the seafloor topography using a depth finder.
echo sounder; sonar depth finder
Standard kanji spelling for a depth-measuring instrument.
Alternate kanji spelling using 器 instead of 機; both are used for instruments.
Compound of 測深 (sokushin, 'depth measurement') + 機 (ki, 'machine, instrument').