It all depends. Sometimes people get a survey and arent willing to fix whatever is wrong. But you might be. I just bought a boat where the guy had bought it a year before, fixed everything on the survey and then found out he needed major surgery and so had to sell the boat. I did my own survey anyway but having the old one played a part in getting me to the point where I made an offer.
And as for how recent is recent enough to just accept it, how long does it take to run aground?