I bought a 1996 cajun bay boat about a year ago , Shortly after I noticed a soft on deck . It seems with each use it is getting bigger. I clearly have a big problem. I realize that the boat rots from within , so If i want to have the floor , stringers and transome replaced by a professional. What would be a rough cost i could expect ? the boat is 21 foot. If anybody has done this please tell me what u had to pay. thanks