(nautical) The scientific measurement and description of the physical features and conditions of navigable waters and the shoreline.

(physics) The scientific study of fluids in motion.

(nautical) A wing attached to the hull of a ship that raises it out of the water when travelling at speed and thus reduces drag. / (nautical) A vessel equipped with such a device.

(nautical) To operate or use or ride atop a hydrofoil wing on a hull so equipped.

that generates electricity by converting the energy of moving water, or of steam escaping under high pressure / of or relating to the electricity so produced

An instrument that floats in a liquid and measures its specific gravity on a scale.

a transducer that converts underwater sound waves into electrical signals, rather like a microphone

(physics) The scientific study of fluids at rest, especially when under pressure.

An outlet from a liquid/fluid main often consisting of an upright pipe with a valve attached from which fluid (e.g. water or fuel) can be tapped.

(chemistry) Containing combined water; hydrated.