Fathometer fathomer • fathomless · · · Info · Definitions · Synonyms · Characters · · Fathometer · · Text Latin · · Script 10 · · Length Definitions · · · (noun) depth finder for determining depth of water or a submerged object by means of ultrasound waves. Synonyms: sonic depth finder, fathometer. · · Noun Definition 1 Synonyms · · · sonic depth finder · · Synonym 1 Characters · · F latin capital letter f U+0046 a latin small letter a U+0061 e latin small letter e U+0065 h latin small letter h U+0068 m latin small letter m U+006D o latin small letter o U+006F r latin small letter r U+0072 t latin small letter t U+0074