I have only been on Greason 1 time. Went up there to do a little boat racing. beautiful lake!

Guys, I need some advice.
Due to the long drive my wife has to get to work, she started car pooling with a guy from work. It seemed to work out pretty good at first but then she started getting home later and later. Sometimes she stays several hours late at work. I noticed the other day that if I was up and around she would get out of his car and come right into the house. But if I was in bed and the lights were out they woould just sit in the drive way for a long time. Last night I decided I would turn out the lights and hide behind my boat and just see what went on when she thought I was asleep. I was not prepared for what I saw. As I stood there behind my boat when they pulled into the drive, the headlights illuminated a crack in my prop. I need to know whether I should get it repaired, or just buy a new one?