Hydrofoil stabilizers, sometimes called hydrofoil fins or outboard stabilizers, are a rigid "wing" that bolts to the cavitation plate on outboard motors as well as some I/O engines. As the hydrofoil moves through the water, it acts like a wing, raising the back of the boat in the water. This helps boats improve their hole shot and maintain a plane at lower rpms, which can improve fuel economy. By raising the stern the trim is adjusted and the boat planes with the bow in a lower position, which increase visibility and safety.