That is a BIGBOY! I had something happen like that. 2 weekends ago, i sat in the stand all evening, didnt see anything, so i got out about 20 minutes before daylight.(i know stupid) So i walk up to the tank where my dad is and he is watching a 10 about the size of urs but not near as thick and i spooked him. SO we head to the back again to checkmy camera, and my dad says, "Trey what is that" so i look up and there is the 8 i was hunting for not 15 yards beside my stand.
Good luck with that bruiser
