I bought a 2016 Z21 that only had 29 hours. A man bought it new and passed away then the guy that I bought it from purchased it. I am the 3rd owner. I have only had it on water 2 times and as I was wiping it down I noticed this.....any ideas on what caused this? Also, if I am reading correctly the warranty only is transferable to the 2nd owner. I am disspointed and could use any and all advice. It is about 6-7 inches long and near where the gas cap is.