Abstract: A siphon device for use around marinas and the like for siphoning large volumes of water containing debris and foreign matter without clogging thereof. The siphon includes an ell member having an input and an output opening of the same size, a hydraulic pressure input stub member along the larger outer curved portion of the ell and a nozzle element extending only a short way thereinto. The hydraulic pressure input nozzle element being of approximately one-fourth the diameter of the ell input and output openings and provided with diagonal or spiral grooves internally thereof for effecting a swirling action of fluid inputted thereto under high pressure.