Water-Ma-Trout is a road and an industrial estate on the northern edge of Helston in west Cornwall, England, UK.
Its name started as Cornish dialect English for "wet my throat", here used as a name for a dry field. An earlier, and perhaps, more acceptable suggestion is that this name is a corruption of "waterman route", due to the water supply towards one of the sources of the River Cober.
A range of industries are based around the estate, such as the scuba gear factory A.P.Diving and Helston Gunsmiths.