Steve,
I'm not sure what a "landing" is, and I looked very closely at the pix you attached, but I could not see any cracks. If you are talking about the slight difference in blue color of the waterline gelcoat, about a foot aft of the bow, that is 100% cosmetic.  When the boats are first pulled from the mold, an inspector goes around the boat with a purple marker and circles small defects in the gelcoat.  Another worker goes around and applies new gelcoat in that area to fix the small defects.  Over time, the slight difference in the pre- and post-mold gelcoat mixtures will change color at different rates. I would not know this if I had not taken a factory tour and asked questions about a brand new hull with purple circles on it.  Both my 1987 C36 and 2006 C400 had/have those slight waterline color differences. They tend to disappear with a fresh coat of wax, and appear more at the end of the season.  Hope this helps.