that looks to be just paint off the skeg, no big deal. Hang out anywhere shallow and it happens. The "stain" is a wet spot from not having the cover support pole up. You can see where the water sat in the cover at the support pole position and leeched thru. Tape might be leftover from sealing the front edge of the cockpit cover for a long road trip. Probly took pics and got it them up as soon as it got there.