depth finder

English Thesaurus

1. navigational instrument used to measure the depth of a body of water (as by ultrasound or radar) (noun.artifact)

hypernym	:	navigational instrument,
definition	:	an instrument used for navigating (noun.artifact)

hyponym	:	fathometer, sonic depth finder,
definition	:	depth finder for determining depth of water or a submerged object by means of ultrasound waves (noun.artifact)