How To Remove Mildew Stains From Vinyl Boat Seats

Boating is one of my favorite warm-weather activities, but discovering mildew stains on my vinyl boat seats can ruin it for me. 

Mildew is a fungus that grows on surfaces exposed to humidity and warmth.

This makes vinyl boat seats the perfect place for mildew to flourish. 

Luckily, mildew stains don’t have to ruin a boat trip, and this article will teach you how to remove mildew stains from vinyl boat seats in a quick fashion.

What You’ll Need

You need a few simple things to remove mildew stains from vinyl boat seats. 

Vinyl Cleaning Spray

It is important to buy a cleaning spray specifically made for vinyl because it is specifically formulated to remove mildew stains while protecting your vinyl boat seats.

The readily available non-greasy sprays are best because they dislodge the mildew from the vinyl without damaging it.

As you’ll see in the video below, I came across CLR PB-CMM-6 Mold and Mildew Stain Remover, and it has been a life-saver for removing mold and mildew.

Soft Brush or Sponge

Whether you use a brush or sponge, make sure it is soft and flexible.

Using a hard-pointed or an abrasive brush increases the likelihood of damage to your vinyl.

Instead, use something gentle to scrub the mildew without damaging your vinyl boat seats.

I’ve had great success with the OXO Good Grips All-Purpose Scrub Brush from Amazon.

Microfiber Cloth

A microfiber cloth is necessary to wipe the mildew off the vinyl.

It cleans better than cotton or silk because it removes germs from smaller nooks and crannies without scratching or damaging your vinyl. 

Magic Eraser

Magic Erasers are a cleaning product capable of successfully removing mildew, so they are great to have on hand after your first cleaning cycle for stubborn mildew stains. 

Protectant Spray

I recommend the UV protectant spray because it will protect your vinyl boat seats from harmful ultraviolet rays while also preventing the return of the mildew stains you just worked so hard to remove.

I recommend this step because it reduces the number of times you have to remove mildew stains from your vinyl boat seats.

Video Of How To Remove Mildew Stains From Vinyl Boat Seats

Here is a video demonstrating how to remove mildew stains from vinyl boat seats.

Written step-by-step instructions are below.

Step-By-Step Instructions For How To Remove Mildew Stains From Vinyl Boat Seats

Removing mildew stains requires some work, but once you’ve completed these six simple steps, you will be able to enjoy your vinyl boat seats once again without the mildew.

#1. Remove Excess Debris From The Seat

Wipe the seat down gently with a damp cloth to remove any dirt.

This helps the vinyl cleaning spray have direct contact with the mildew stains.

#2. Spray The Vinyl Cleaning Spray On The Boat Seat

Spray the vinyl cleaning spray directly on the vinyl, and let the spray sit for 5-10 minutes to allow the cleaning spray to work itself into the mildew stains.

Pro tip: Make sure your vinyl cleaning spray covers every inch of your boat seat. 

#3. Gently Scrub The Seat

Gently scrub the mildew stains with a sponge or a soft, flexible brush.

Pro tip: Don’t use a hard-tipped brush or an abrasive to scrub mildew stains on vinyl.

Both are likely to damage your vinyl.

#4. Wipe The Seat With The Microfiber Cleaning Cloth

Use your microfiber cleaning cloth to remove the mildew.

Work gently, scrub in a circular motion, and push the microfiber against the vinyl with your fingers.

Repeat this step until the mildew stains are gone.

Pro tip: Microfiber cleaning cloths are great for cleaning because they can safely be washed and reused.

Once you have finished wiping up the mildew, wash your microfiber cleaning cloth, and use it the next time you need to clean.

#5. Use The Magic Erasers To Remove Tough Remaining Stains

Despite our best efforts, some mildew stains are stubborn.

If you find you have a stubborn stain, use your Magic Erasers to erase the last of it.

If you need to order Magic Erasers, check out these Mr. Clean Magic Eraser Extra durables, Cleaning Pads with Durafoam, 10 Count.

Pro tip: Once you have scrubbed the mildew stain with the Magic Erasers, wipe your seat again with your microfiber cloth to remove the remaining mildew.

#6. Spray The Vinyl Boat Seat With Protectant Spray

Spraying your vinyl boat seats regularly with UV protectant spray helps maintain your vinyl and protect against further mildew stains, allowing you to enjoy your boat for many years to come.

303 Marine UV Protectant Spray for Vinyl is a best seller on Amazon and gets excellent reviews.

Commonly Asked Questions About How To Remove Mildew Stains From Vinyl Boat Seats

Can I use home remedies instead of purchasing commercial products?

Yes, you can use home remedies, but I don’t find them as effective or safe for the vinyl as using a vinyl cleaning spray.

Here are a few home remedies you can try.

Dissolve two or three drops of mild dish soap in room temperature water for new mildew stains.

Mix a cup of laundry detergent in two cups of water to lighten stubborn mildew stains.

Then, use equal parts water and alcohol to remove the mildew.

Combine white vinegar and water in equal parts.

Treat mildew stains with ammonia diluted at one tablespoon of ammonia for every ¼ cup of water.

If you choose this route, be careful about handling the ammonia because ammonia can damage the vinyl and hurt people if it is mishandled. 

Can I use bleach?

You can use bleach in a diluted form, but I do not recommend it.

Bleach damages vinyl by drying it out, and vinyl manufacturers recommend against using bleach. 

Do I need to replace my seats?

Most likely, no.

If you clean your boat seats regularly and at the first sign of mildew stains, you will be able to enjoy your current vinyl seats for years to come. 

If, however, you find your mildew stains are frequently recurrent, the mildew may have worked itself through the vinyl and into the seat pads.

At that point, you may want to replace your seat pads and the vinyl over them.

Your boatbuilder or an online upholstery shop may sell replacements.


I hope you have enjoyed learning how to remove mildew stains from vinyl boat seats.

Now that you, too, know how to remove mildew stains from vinyl boat seats, you will never be caught off guard by mildew.

All you need are the right cleaning products and a vigilant eye, and you will be able to enjoy your vinyl boat seats without mildew stains.