Abstract: Apparatus for removing oil and other flotsam from water, including an elongate tank with an inlet at the upstream end for introducing a fluid and flotsam mixture into the tank to provide a mean fluid level in the tank. A plurality of longitudinally spaced, vertical dams extend transversely across the tank dividing it into longitudinally spaced zones, each of the dams having an upper edge spaced below the mean fluid level in the tank. A vertical weir is provided in each zone extending across the tank so as to divide the zone into an upstream section and a downstream section. Each of the weirs has an upper portion which extends above the mean fluid level and a lower edge spaced above the bottom wall of the tank. The weirs are preferably angularily positioned relative to the longitudinal axis of the tank so as to converge with the side wall of the tank at an acute angle to provide a collecting corner for receiving flotsam.