Water type can vary within the same general locale, too. "Here in New Jersey, inshore and offshore are not the same," says Seidel. "Some bays will be different, too. For example, the eastern side of the bay may be more salty, so on that side you'll have more animal fouling, while on the west side there's more slime fouling. It's a salinity issue. And some areas, such as the mouth of the Connecticut River, have a lot of slime and grass growth - especially in the early spring after everybody puts lawn fertilizer down, so the paint can become overwhelmed. Another spot, Boston Harbor, was long notorious for high fouling because of sewage discharge that put a lot of nutrients in the water."