The white spots can come from the salt. But the de-icer that they throw on the roads the new chemical stuff is probably the cause. Sharkhyde is only a protector or covering you will have to acid wash or polish out the spots . You need to polish your boat then clean it with thinner they recomend a type of cleaner to get the polishing compounds off of the aluminum so the sharkhyde will adhere. Once you use the thinner or cleaner you polish job will look hazy. Just take a clean soft cloth and polish it back to a shine then apply sharkhyde. It is alot of work but worth the effert you wont have to do it again for years.