I am unfortunate enough to have an older boat which has bold colors on the hull. What is it that brings the oxidation back so quickly? I had it buffed out last year and it sat partially covering the areas with a cover. It was never placed in the water after buffing. Both areas, those under cover and those not, had oxidation re-appear in a very short time. Why is this and is there anything shy of repainting to correct this? I know of a boat specialty product but it is expensive and it needs to be reapplyed every so often. Its sort of a last resort.