mareograph
/ˈmarɪə(ʊ)ɡrɑːf/ /ˈmarɪə(ʊ)ɡraf/noun
An instrument for automatically recording the rise and fall of the tide or the height of waves over a period of time; a tide-gauge.
Origin
Late 19th century; earliest use found in Isaac Funk (1839–1912), publisher and reformer. From classical Latin mare + -o- + -graph, either as a re-formation of earlier marigraph, or independently after a foreign form; compare French maréographe, marégraphe, Swedish mariograf, Spanish mareógrafo, Italian mareografo.