I have the exact boat in the exact color, and have a few of those character lines as well after 15 years and several thousand river miles. Sadly, most of the damage has been from transport on the trailer rather than from anything that happened on a river. With Aires it is all cosmetic on the outer hull anyway, but I've done the Aquaseal thing on a couple of them just because they kind of bug me. I might have to try that green sharpie idea!
And look what I found in my office - the old girl is gonna look brand new once I've re-surfaced the hull with sharpie!