1979 23' Seacraft

[CCNautical]

I am looking at purchasing a 1979 23' Seacraft Center Console. It seems to be in good condition. The one thing I noticed is on the port side deck somewhat near the back of the consol there was a spot that had a noticeable bounce to it when you stepped on it. The bounce spot was maybe 2 feet square. The rest of deck seemed solid bilge and anchor lockers seemed dry. Is this common in this model - what could I check on my own before hiring a surveyor. The seller stated the bounce never bothered him and he has a similar bounce in his newer boat. Any help would be greatly appreciated.