Hey, I am looking at a 92 Formula 336 that for at least the last three years has been slip kept in fresh water from June 1 to Oct 1 each year. It has NO bottom paint. The guy says he tries to pull it out once in like August to wash the slime off and then puts it back in for the
rest of the season. Then, it is washed again, winterized and stored on a trailer. Is this boat gonna peg the moisture meter on a survey because of this? Should I even consider this boat after being left in the slip for 4 months a year without bottom paint?

Is this the one in Buffalo? I don't care much for slipped boats after having a bad experience with my last one, a Regal. Boat had low hours and was clean, but I also discovered a rotten transom after buying it. Definitely an expensive mistake I made.

It would not scare me away! But i would get a recent survey, and go from there!

Yeah. It wasn't my first pick, but after talking to the guy seems like it could be an option now. You know the boat?

Whatever boat I decide on, I will definitely get a survey. BUT, there a several to consider. These survey expenses can add up. That's why I figured I would see if leaving a boat in a fresh water slip is harmful or not given the porosity of these fiberglass boats.

It is not the porosity that makes for trouble... it is only the hole from outside generally causing the problem when they were not sealed or not sealed properly or when the silicone dried out allowing water in... like exhaust holes for example. As for the hull itself, there is no problem being in the water

I disagree, blistering potential is always there.

I agree, over time, Fiberglass becomes more porous and will absorb some water. I would definitely get a survey and a real good moisture meter test on all parts for piece of mind. 500 survey could save you Thousands, even 10s of thousands. Plus you have a bargaining tool when negotiating price

For a boat that is over 25 years old, that has been left in the water for a substantial period of time, I would assume the transom is rotter, it's a wood transom. Formula uses a fiberglass grid structure under the floor, with some wood to secure things too. Have it checked, and redoing the transom isn't the end of the world if the rest of the boat is clean and you get a good price on it.

I have been keeping my boat in a fresh water slip for the last 8 years. I pull it 2-3 times/summer to clean the bottom. No blisters or issues.

Water temperature and other factors come into play. I have seen boats in colder fresh water be able to sustain a season floating in a slip. Here in Lake of the Ozarks there is no way this would work. The hull would be covered in scum and we have seen hull blisters and paint blisters in times as little as 30 days afloat.