Harbor Safe Marine Care Products
Waxes, Cleaners & Polishes

Marine 31 Mildew Remover 32 oz.

Marine 31 Mildew Remover 32 oz.
Remove stubborn mildew stains – FAST!

Marine 31 Mildew Remover quickly and safely removes stubborn mildew stains on virtually all marine surfaces, including vinyl seat cushions, rubber fenders, fiberglass, gel coat, canopies, and more! Marine 31 Mildew Remover forgoes volatile cleaners and instead relies on smart chemistry; even severe mildew growth is no match for the incredible cleaning power of Marine 31 Mildew Remover.

Marine 31 Mildew Remover is the best boat mildew cleaner available!If you’re a boater, chances are you’ve dealt with stubborn mildew stains on vinyl cushions. If you’re reading this product description, chances are you’ve been less than satisfied with the performance of other so-called marine mildew cleaners. Fortunately for you, we’ve compared Marine 31 Mildew Remover against other marine mildew cleaners and have found that it removes mildew stains faster, with less effort.

Not all marine mildew removes are created equal! Most over-the-counter marine mildew cleaners rely on heavy concentrations of bleach and other volatile chemicals that actually cause more harm than good. Marine 31 Mildew Remover removes stubborn mildew stains without discoloring, dulling, or drying out vinyl surfaces. Best of all, it still retains the powerful cleaning ability to remove mildew stains – FAST!

Use Marine 31 Mildew Remover on:
  • Vinyl cushions and chairs
  • Rubber fenders
  • Fiberglass
  • Gel coat
  • Canopies
  • Boat tops
Marine 31 Mildew Remover works wonders for household cleaning as well! Use this professional strength formula to clean tile, grout, showers, bathtubs, counters, and sinks.

Marine 31 Mildew Remover works FAST!Directions:
  1. Spray directly onto surface and allow 1-3 minutes for penetration.
  2. If necessary, agitate surface with a brush or terrycloth towel.
  3. For stubborn stains, allow cleaner to penetrate for 5 minutes before agitating.
  4. Thoroughly rinse and dry surface.
  5. Follow with Marine 31 Mildew Guard to protect treated surfaces.
32 oz.

Made in USA

Federal regulations prohibit the shipment of this products by air, UPS 3 Day, UPS 2, or US Mail. This item is shipped by UPS Ground only. Sorry but no APO or FPO addresses.

Marine 31 Mildew Remover 32 oz.
Item #: M31-371
Our Price: $29.99, 4/$89.97
Availability: Usually ships the same business day

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Product Reviews

48 Reviews
92% (44)
6% (3)
0% (0)
0% (0)
2% (1)
98% Recommend this product (47 of 48 responses)
Bel Air, MD
Return customer
We've tried everything to get rid of the mildew on our vinyl pool lounge chairs. I found this online and read all about the great ratings so I decided why not give it a try.
It truly is amazing! It completely removed all the mildew and kept is away! We have 8 lounge chairs and the smaller bottle cleaned 6. Reordered more but bought the 32 oz to last through the summer.
Great product and does exactly what it says. Again, I've tried EVERYTHING for the past 3 years and I will no longer waste my time on alternatives. Marine 31 will be all I use each season!
trinity, alabama
This product does what it says it will do.
I will purchase again
Brandon Fl
Better than expected
I bought a bottle with doing some research and hoping for the best. I was so happy that the product worked as advertised and turned my seats from basically nasty to DAMN CLEAN. I. impressed.
Mobile, Alabama
Loved this product
It worked beautifully without fuss... boat seats look brand new. Had doubts they would clean up but this did the trick.
ConsShipping cost & It took to long to arrive... I am Amazon spoiled 😜
Our older pontoon looks like new.
Indianapolis, Indiana
It works!
We thought we had our boat seats pretty clean until using Marine 31 - they're now next level clean. Great stuff so far!
Nokomis, Fla
Marine 31 is the best product EVER for removing mildew and ALL stains from marine vinyl. Easy to use even; literally spray on, let it work (some spots take longer than others), and wipe it off. I used it in the entire cockpit of my 2001 boat, and it doesn’t look like a used boat at all!! Love this product!!
Unbelievable product cleaned all seats like new in 50 minutes on my 24ft pontoon!
Cicero In.
Great cleaner
Marine 31 mildew cleaner works best. Little bit goes long way. Cuts the time .
Balaton, MN
A great product.
It was absolutely amazing how well this cleaned our pontoon seats. They almost looked new.
New Hampshire
It works!!
I’ve tried everything to get rid of those gray mold stains on the boat. This is the only thing that worked!
Chesapeake City, MD
Good, but not as great as I had hoped.
I was hoping to eliminate the black dots and yellow/orange stains on our pontoon seats. While this product definitely made the seats cleaner, it really did nothing for those issues. We wound up having to use a wipe on paint product to cover the stains.
Pros- Partially cleaned seats - Fair price
Cons- Didn't eliminate spots - Didn't eliminate certain stains
Simply the best
Unlike other mildew products, this one really works.
ProsCleans real problem areas if you follow directions.
ConsMust use gloves! Protect your hands.
This one works!!
I have tried them all. This is the ONLY product that works.
Naples, Florida
Saved us thousands in replacement costs!
We have outdoor furniture made by Ethos. They are outdoor wicker and cream colored “marine leatherâ€. After 5 years of being in the lanai they were starting to mildew even though we cleaned as suggested by the manufacturer. Heartbroken we had almost decided to replace them when I did a little searching on the internet. I purchased this product with the mindset of having to replace anyway, so no harm. I literally sprayed and walked off to get a cloth. By the time I came back, less than 2 minutes, most of the mildew was running down the sides. I simply wiped it off!!!! There were 2 areas on 2 chairs that needed extra applications but EVERY SINGLE PIECE LOOKS BRAND NEW! I am heartbroken I didn’t think to take a before photo. You have a devoted fan and forever customer! (I purchased all the other products that go with this too!)
ProsEffective!!!! It really works!
ConsCan be a little harsh smelling, so use in a well ventilated area.
New Port Richey, FL
works great
best product on the market for mildew removal
Conslittle pricey
Naples, FL
worked like a champ
It was like night and day. I was very skeptical after seeing a video of how fast and well it worked. Tested it out on one section after i took the covers off the boat. Was so easy, i didn't have to agitate the area at all. Would highly recommend this for anyone who has those mildew spots. Going to buy the mildew guard. Looking at other products they have.
Girard, Ga
Best yet!
I have tried all sorts of cleaners to remove mildew from my boat seats. Marine 31 is by far the best I have ever used!!
Okeechobee, Fl
Works great with very little effort!!
Best ever used!
Utica, New York
Amazing Product! I am a believer!
I remained skeptical even after watching many You Tube videos . But I am a believer now! I have a 1996 pontoon boat with seats that are in great condition but were covered with the unsightly black mildew stains.
After just 1 application of Marine 31 Mildew remover the mildew was gone!
Dana Point
Awesome Product!!!!!
I just used Marine 31 on my Boston Whaler backseat cushions that had spots that I could not get rid of. They were small dark spots and I figured I would have to live with them until I used Marine 31. I wish I took a before picture but I was too excited to try this stuff out and I don’t think I was a true believer until now.

Thank You!!!!
Louisville, Ky
Best Product i have found!
I have used multiple mold removing cleaners on my boat and nothing comes close to this one! My seats have not looked this good in years! Thanks
Boca Raton
This stuff is amazing
It works as described
ON, canada
Thank you
It is a masing how it remove mildew, dirt and stain of my boat seats and interior panels.
I would recommend to everybody ho has to deal with mildew issues.
Thank you
Effortlessly removes stain in marine vinyl.
We were going to replace the steering wheel on the boat because it was so deeply mottled with dark stains that we thought would never come out, but it came out new looking with this stuff!
Actually after a year of sitting out in the weather, almost every surface had mildew/mold stain, now the entire boat looks new!
ProsIt took longer to read the directions than it did to remove a stain!
ConsMake sure you read the warnings on the label. Use in well ventilated area.
Lake Anna
Wow this stuff works great!
It's like magic. Best decision to buy this
Works Great
self cleaning right out of the bottle amazing,
ProsSpray and your done no scrubbing no extra work.
Emily Minnesota
If I knew that the mildew was LITERALLY going to vanish before my eyes I would have videotaped it! I am thrilled to have found a product that really worked! To be able to remove mildew from a 36-year-old pontoon is amazing! I will buy again; it's worth every penny!
I have used many other products and didn’t have too much confidence I could get my vinyl clean. Marine 31 changed that! It works wonders and had my 16 year old vinyl looking new. Great product.
Your mildew remover works like magic. It even removed an old mildew stain that was on our seat for years. Awsome product. Worth every dollar.