Contact with salt water will reduce the life of the fixture. We have a lifetime fixture guarantee, but it is not valid near salt water. The steel is 1/8 inch thick on the 4x4 light body, high grade structural steel, and the cap is cast iron. These materials should last many years in your environment, but as I mentioned we would not be able to honor our lifetime guarantee. We will be introducing copper and stainless steel fixtures this winter and our guarantee will apply to those in any environment.