Keeping things clean is not only healthier for you boat it is also healthier for the environment and is relatively simple. To prevent the bilge discharging oily residue always keep your engine well tuned. This will help prevent fuel and oil leaks and ensure that your engine runs efficiently. You should also secure an oil absorbent pad in the bilge beneath the engine. This will catch any drips. Check and change the pads regularly and dispose of them at a marina or local hazardous waste centre.