(pronounced saysh) A rise and fall of the water level

in a marina or harbour occurring at an interval of a few minutes and unre!ated

to the ordinary tidal rise and fall or to regular swell running in from the

sea. May be caused by changes in barometric pressure, or by waves of very long

period which would not be noticeable in the open sea. In ordinary landsman’s

language you would probably say ‘surge’.