I'd also vote for the bleach. I have a hot tub, and when it is not in use, rain water gets in it. Mold forms on the bottom surface of the vinyl cover, literally black. Nothing takes it off. After a couple of weeks of chlorine gas after the tub is running, the spots disappear, and it's back to its regular color. You have to be patient, and keep it wet with a mild solution bleach.

Michael

An underground mine !!!!!!!

What in the world were you thinking man??????

Sure, the temp was an even 50-55,,,,,,,,,,,,, and the humidity was a never changing 90-100 percent!!!!!!!

I feel bad for your problems, but that was a really goofy place to store your boat.

WD 40 Really? I'll give it a try.

Jomax as well. I'll look for it.

T Bird, not really goofy placxe to store a boat. Very Common in Pa. There are literaly thousands of large boats, motor homes and collector cars stored in underground mines in Pa.

How they get em down those itty Bitty holes ?

let her air out before you turn the key

Here is the result, paper towels on the seats, sprray with 75% clorox 25% water. Keep soaking the paper towels. Did this for three days MOLD IS GONE!!!! Thanks to all for great suggestions!!

is the seat still there too?

I'm telling you I tried every suggestion posted here and then some. That is the only thing that worked. No seat damage at all. Rinsed them very well and then put a few coats of Frenzy vinyl conditioner on. Looks brand new.

Krazy kleen , my usual spring cleanup. Rinse well!