A floatable raceway (1) for cultivating fish comprising a partially submersible tank (2) for containing fish having a base (5), opposing sidewalls (6), a gate assembly (8) having removable gates (10, 11) at a water discharge end of the tank (2), and an end wall assembly (7) at a water intake end of the tank (2) having a ramp (9) extending downwardly to the base (5) and towards the gate assembly (8). The raceway (1) also includes floats (3) extending the lengths of the sidewalls (6) for keeping a top of the tank (2) above water level, an airlift assembly (4) connectable to an air supply for introducing oxygenated water to the tank (2) at the water intake end, and a baffle (14) for directing the flow of water through the tank (2) along the base (5). The raceway (1) has a pair of screen gates (10) allowing the movement of fish wastes therethrough and a pair of stop gates (11) for substantially preventing water from discharging from the tank (2).