Bathometer and Dynamometer

noun

• An instrument that measures the depth of water.
  • synonyms: bathymeter

(n.) An instrument for measuring depths, especially one for taking soundings without a sounding line.

noun

• Measuring instrument designed to measure power.
  • synonyms: ergometer

(n.) An apparatus for measuring force or power; especially, muscular effort of men or animals or the power developed by a motor or that required to operate machinery.