How big is your friend, all the manufacturers have guidelines on paddler weight. However if you are like me, very short legs and quiet heavy you have to compromise between size of boat and how much water you displace. Things to ask, where has the boat been and if someone trys the its been on a few rivers and mostly surf, creek boats are not very good in the surf as many have a displacement hull. Okay things to ask what type of boat? How old? Where has it been used? Next checking it out if looks like a club boat you knowe it has been well used and probably repaired. Check out the dagger, phrayna and other websites for specs of boats.