Here is why I asked the question: I read a long time ago that the reason air pollution from diesel fumes is more dangerous than from gasoline fumes is that diesel spews out long-chain polymers into the air.

Now we have a motorhome with a rear-engine diesel, so the exhaust fumes go directly back onto our boat hulls whenever we are traveling, making the hulls all black and yucky. Our first instinct was to wash them, but another instinct is to avoid unnecessary work, so I came up with the idea that we should not wash the hulls because maybe they have long-chain polymers all over them, making them ugly but fast.

What do you think? Is that possible? If so, maybe our boats are illegal.

(P.S. Before somebody suggests it, yes, we do plan to run the exhaust pipe up to the top of the motorhome so our boats don't keep turning black.)