Marine 31 Mildew Stain Remover

Used Marine 31 Mildew Stain Remover on my South Bay pontoon that spends most of the year in covered dry storage in Arkansas humidity. After a long winter the vinyl seats had significant mildew staining that I was skeptical anything could fully remove. This product proved me wrong. Sprayed it on — let it dwell a few minutes — light scrubbing with a soft brush and the mildew staining came off remarkably well. The results were impressive considering how long the mildew had been sitting on the vinyl. One thing to be aware of — despite the product not listing bleach as an ingredient the smell is unmistakably bleach-like during application. It dissipates after rinsing but if you are sensitive to bleach smell you will want to work in a well ventilated area or wear a mask. Important tip — thorough rinsing after cleaning is essential. Make sure you rinse the vinyl completely and do not leave any product residue on the seats. Taking the time to rinse properly makes a noticeable difference in the final result and protects the vinyl long term. The important thing is it is safe on marine vinyl — no discoloration or damage to the seats whatsoever. Followed up with 303 Aerospace Protectant after the seats dried and they look better than they have in years. For anyone dealing with mildew on boat seats — especially boats stored in humid environments — this product delivers real results. The smell is a minor inconvenience for the cleaning performance you get. Highly recommend.

It’s the only thing I’ve tried that does remove old stains on my white seats in my Chaparral boat. Awesome product!

It works!!! I also used it on our shower and it worked!!! Make sure you ventilate as it does cause fumes!!! Pretty strong stuff!!!

Just bought a pontoon boat. The seats were in sad shape. I sprayed this on the seat a waited 5 minutes before taking the hose to rinse it off. Amazing results. It does smell like bleach, so I’m waiting to see if anything happens with the carpet. But very happy so far.

Worked ok but not great

Absolutely amazed by how fast this worked! I sprayed it on, let it sit for just a short time, and the mildew practically disappeared with minimal scrubbing. It cleaned years of mildew buildup and left everything looking like new again. I was honestly shocked at how well it restored the surface without damaging anything. Super easy to use, powerful, and definitely worth every penny. If you’re dealing with stubborn mildew stains, this is hands-down one of the best cleaners I’ve ever used. Highly recommend!

I'm here to tell you, this stuff is AMAZING! I keep my boat clean, inside and out but no matter what I've done in the past, the seats have always gotten some mildew spots on them. I tried other products and they do not work. Sprayed this on per the directions, let it sit a few minutes, stains gone. My boat vinyl looks brand new. Getting ready to order the protectant.

This stain remover really works on our boat!