A offshore system for storing oil includes a hull. The hull includes a buoyancy compartment and an oil storage compartment disposed below the buoyancy compartment. The oil storage compartment has an upper end, a lower end, and an inner cavity. In addition the system includes a water port in fluid communication with the inner cavity and configured to allow water to exit the inner cavity. Further, the system includes an oil heating and circulation system coupled to the hull. The oil heating and circulation system includes a suction line having an inlet disposed in the inner cavity proximal the upper end. The inlet is configured to draw oil from the inner cavity. The oil heating and circulation system also includes an oil heater coupled to the suction line and configured to heat oil passing through the suction line. Further, the system includes a return line coupled to the oil heater. The return line includes an outlet disposed in the inner cavity and vertically positioned between the inlet of the suction line and the water port.