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Harbor Safe Marine Care Products
Waxes, Cleaners & Polishes

97 Reviews
89% (86)
4% (4)
2% (2)
2% (2)
3% (3)
92% Recommend this product (89 of 97 responses)
By Mike C
Greenville SC
May 19, 2019
Absolutely fantastic product
I've been struggling with the cleaning of moldy and mildewed vinyl seats for over 25 years. I have tried just about every cleaning product out there with mostly disappointing results. I purchased Marine 31 after seeing stellar reviews and expected nothing better than the others. I sprayed the cleaner on my very nasty seats and console then went off to do other boat related tasks. When I came back 5 minutes later the vinyl was 95% clean. No scrubbing, no swearing, awesome.
ConsA bit pricey
By Al
Alma Georgia
May 17, 2019
The beat
Don’t waste your money on other products like I did. After frustrating myself with trying everything imaginable, I ordered this as a last ditch effort. My boat seats look new again!! Just trust me. This stuff is wonderful.
By Clayton
Bushnell, Illinois
May 10, 2019
Great Product
I've been around boats 34 years, only thing I've seen that actually works the first time!
By "Bob"
New Jersey Shore
May 9, 2019
Amazing Results
When removing winter shrink wrap each year there is always significant mildew on the padded interior of the boat. I sprayed the passenger side, turned and sprayed the driver's side and in that short time the original mildew (passenger side) was gone! Not just "better", gone. From just about totally covered to white again.
By Jon
May 9, 2019
Works amazing
I had black spot from two years ago that I scrubbed with other products and was unable to clean, this stuff took it off in minutes with very little effort. Make sure your in a well ventilated area or where a mask!
By Luke kilroy
North Carolina
May 6, 2019
Mold killer
Sprayed it on mold between my leaning post seat and it was gone in a minute
By Robert L.
Corpus Christi, Texas
May 3, 2019
Never believed that it would work as advertised
AMAZING. Vinyl Boat seats were heavily stained with deep dark mildew spots, literally everywhere. I had tried several other products and has scrubbed and scrubbed with absolutely zero results. Then i came across Marine 31. I was very skeptical that it would produce the results that i had read ans seen, but this product actually worked as advertised. No scrubbing whatsoever was even necessary. Sprayed directly on the seats as instructed and then watched the miracle take place. Well worth to $20.00 investment, as i was literally shopping around for prices to have the seats recovered.
ProsSuper Simple, and it ACTUALLY WORKS
By Mike
April 29, 2019
Wow wow wow
All I can say is wow. Great stuff. Saved me thousands not to do my seats a recover
By David Weigle
Chapin, SC (Lake Murray)
April 24, 2019
Absolutely amazing!!!
My boat was embarrassingly nasty. I am providing before and after pictures. I tried every commercial product I could find and many home remedies, including hydrogen peroxide, clorox both diluted and undiluted, muriatic acid, vinegar, you name it. Nothing worked. I decided to try Marine 31 but I was skeptical. Well, it works beyond my wildest expectations. I am ordering two more bottles today. Turns out I could only add three pictures so one "after" is missing but you will still see the results.
ProsWorks as advertised. The best I have found
ConsExpensive (but I guess it's worth it.)
By 1h20skier
April 15, 2019
I really wanted this to work!!!
Maybe my expectations are to high. But after watching YouTube reviews of this product, I thought it would take out the mold stains. But after trying it again and again, it DID NOT take out the mold stains on my vinyl boat seats I am referring to the dark spots and their removal. I first clean the area, then after that area dried, I sprayed on the the remover, waited 15 min, agitated the area with a brush and rinsed. No noticeable difference from before and after.
ConsDid not work for my mold stains on my vinyl seats
By Doug
Marina del Rey, CA
April 12, 2019
I saw Marine 31 on a on-line video. The user was very enthusiastic about the product, so I gave it a try. I had severe mold issues on my vinyl seat cushions. I had tried 303, vinegar, bleach, oxyclean, nothing worked. I sprayed the Marine 31 on, let it set as directed, and wiped it off. Honestly, it was that easy! Done. The cushions are perfect!
ProsReally easy and effective.
By Tracy
palm coast fl
April 12, 2019
this works great
i tried many other items and this was the best
By Jeff
Greenville NC
April 10, 2019
Awesome product
Took the mildew right out of my boat cushions. Had to let it soak a little but did the job.
By Mary Danihel
Goldsboro. NC
April 4, 2019
Best Mildew remover I have used
I purchased this product after seeing a video on how it worked . I bought it to remove the mildew from my vinyl Golf cart seats it worked Beverly well . I will recommend this to all my friends .
By Tommy
Wake Forest NC
March 29, 2019
Mildew remover
Seemed to be nothing but a lot of bleach in the bottle.it cleaned ok but not what I was expecting.
By Aaron S.
Boynton Beach, FL
February 27, 2019
This stuff is AMAZING!!!
Have tried just about every supposed mold/mildew cleaner remover stuff on the market. Tried magic eraser, degreaser and mildew remover combinations, I think Z Cleaner with their z-scrubber (basically heavy duty magic eraser) is the only thing that came close but that stuff takes hours of scrubbing. Saw this stuff online, ceraonlynhad my doubts, But figured what the heck and gave it a shot. THis stuff does exactly what it advertises. Spray it on, wait 3 minutes and boom. Mildew gone. My upholstery is back to beautiful again. Thank you Miracle 31.
ConsSmell is pretty strong. Make sure you are in a well ventilated area. Wear gloves and remove jewelry. Wife?s Silver ring is now seriously tarnished. 😕
By Doug
Salado, Tx
February 9, 2019
Did not work for me.
The stains on my boat seats are still there. Maybe it's not mildew stains but I'm pretty sure it is. Followed the instructions and gave it several attempts. Can't recommend this product based on my experience.
By Brad
Wausau, WI
February 7, 2019
The results don't lie!
I had high hopes of for this bottle of what others called a "miracle". I read reviews, watched video reviews, and was optimistic that it would remove the stubborn mildew from my boat seats (which I had scrubbed and scrubbed with other cleaners before finding this). Even with all my research, I was STILL SHOCKED AT HOW WELL IT WORKED! Again, I had worked on my seats for a long time with other cleaners with virtually zero results. But after spraying on Marine 31, waiting 3 minutes, and simply wiping off with paper towel, I could not believe how well it worked. Almost 100% of that pesky mildew (which I thought was permanent damage) was gone. The seats look like new! I will certainly be buying this company's protectants and other products as well. It's money extremely well spent.
ProsIncredibly effective, easy to use
ConsA bit costly, but we'll worth it
By Wendy Cook
Riverview, Florida
February 4, 2019
Great Product!
The interior of my boat was unfortunately covered in mildew. This product was great! I sprayed it everywhere and within minutes the mildew was gone with a rinse of water! I had some stubborn stains and as the product indicates, you spray it, let it sit for a few minutes and give it a little scrub with a sponge - it came off easily. I was very impressed and will buy this product again!
By Jim Richards
Treasure Island, FL
January 24, 2019
It’s as good as the YouTube videos that I watched about the product. My seats look like new with basically zero effort.
By jjim masserang
lapeer mi
January 14, 2019
worked great on my boat seats. better than anything else i have used
By Terry Campbell
January 2, 2019
This stuff is amazing. We have tried almost every product there is to remove mildew and this works the best. Just spray the stuff on and it works instantly. Our boat was covered for three months and used a whole bottle on the boat, it looks brand new again. I would highly recommend the mildew remover!!
By Carol G.
Greer, SC
December 18, 2018
Absolutely fabulous!
This product was recommended to us to use on the vinyl top of our car, which had become badly mildewed from not being in our garage. We had tried several other products, some of which helped a little, but there was always a final little layer deep in the roof that would not come off, no matter what. With the very first use, ALL the mildew was removed! The roof of our car looks like it just rolled off the showroom floor! We will highly recommend this product to others and will not waste our money trying anything else. As long as we have this car, we will be loyal Marine 31 Mildew Remover users!
By John Yuskaitis
Goodland, FL
December 15, 2018
Only product to buy
I tried a number of other mildew removal products on the seats of my boat. None of them did the job. I saw a YouTube video of a guy had the same issue as me. He tried the same products without success until he got Marine 31 mildew remover. After I saw his results, I ordered a bottle and it worked great. My seats look good again. I will be ordering a gallon as well as some of Marine 31’s other products.
By Neal
Orlando FL
December 9, 2018
It works!
Stored boat with cover for a few months in Florida summer heat and rains. Seat backs had mildew. Much of the mildew came off with white lightening cleaner but stains remained. Bought lime away foaming mildew stain remover several applications stains a bit less but not gone. Bit the bullet ordered Marine 31. Spray it on let it sit a few minutes many stains disappeared but a few remained. Rinsed, reapplied let sit and used tooth brush to scrub it in. All stains are gone. I did get some on my shorts and t-shirt turned them white similar to what bleach does. Did not discolor my 2017 tan seats.
By Mark
Newburgh NY
November 23, 2018
Heavily Mildewed Beige Pontoon Boat Seats: 80% Gone 20% Remain
The stains definitely fade...but not completely. That said, mine was an extreme case as you can see by the "before & after" photos.
ProsRemoves about 80% of a heavy stain
ConsLeaves 20% of a heavy stain.
By Scott
Lakes of Michigan
November 17, 2018
Marine 31 Mildew Remover Review
This worked as needed and shown on YouTube. I've used many other products and was disappointed as they wouldn't remove all the mold spots. Marine 31 Mildew Remover got about 95% of them with little effort other than spraying it on. It does smell like bleach but I didn't have any bleach color spotting that I was concerned with. There are no ingredients listed on the bottle. I will continue buying this product as it's the only one I've found to work as I need.
By Mary Dickason
November 15, 2018
Magic in a bottle
This product is fantastic, works as promised!!
ProsWorks quickly and efficiently
By David
Tampa Florida
November 8, 2018
Best stuff ever
I have tried every thing made for seat mold nothing worked until I found this.follow instructions spray let stand and wipe the mold and mildew away best stuff to have if you own a boat or r.v. Thanks for a great product that does what it says
ProsWorks better than advertised
By Terri Sue
November 7, 2018
Great stuff
Best stuff ever for removing mildew! Better than bleach!
By Bobby Amerson
North Carolina
November 4, 2018
Very good
Only thing I found that really works.
By Walter
Ravenna, Ohio
October 31, 2018
Best I've found
This mildew remover works great, it's the best I have found for removing mildew from my boat seats. Be careful to use gloves, wear old clothes and cover what you don't want discolored. This is strong stuff and worked great for me. I sprayed it on and let it set for 5-10 minutes and then scrubbed the worst areas with the scub brush I also purchased from Marine 31. I also wiped everything down with clear water after using this product. I don't know if this was necessary but I felt it would be good to do so. I applied the Mildew Guard afterwards and the seats on my boat look great
By Don Caudill
Barberton, ohio
October 28, 2018
SHIPPING WAS FAST. Marine 31 is a Great product, It works GREAT. I spray Marine 31 on a golf cart , everyone thought it was a cream colored golf cart. I let in soak in for 10 to 15 minutes and the golf cart was actually white, the seat came out white also. I will buy this product again...
ProsMarine 31 does the JOB. IT WORKS!!! Let it soak in 5 to 10 minutes for Fantastic Surprise!
By Erwin Schulz
October 27, 2018
You need more stars
This stuff worked like magic. I had a severe mold problem after some bad weather and torn covers. I saw a youtube video where a guy had the same problem and swore by your product. I sprayed the seats and waited. I didn't try to wipe it. In an hour I came back and the seats were like new. The mold, and more importantly, the stains that mold leaves behind were gone. Awesome! Erwin Schulz
By Amber
October 26, 2018
Awesome Product
We were so pleased with this product, we had such bad mildew on our boat, we sprayed this on and within a minute the mildew was disappearing before our eyes! We will be buying this again in the future. I have never seen a product work so well on mildew as this!! Try it you wont be sorry!!
By Chris Kruysman
October 26, 2018
They should call it "MIRACLE 31"
After multiple attempts and multiple failures with multiple products (3M, Starbrite, spray nine) this magical bottle arrived and saved the day. Worth ten times the cost! THANKS!
By Steve
October 25, 2018
Was amazing
Absolutely done the job. I thought my seats were ruined. Spray Marine 31 on and it went to work. Now my seats look brand new again. My girl friend bought other cleaner, it would not even touch the mold. Marine 31 is a superior product.
By Jill
Woodstock, CT
October 25, 2018
Best product I have used in 40 years of scrubbing boats!
I read the reviews about the Marine 31 Mildew Remover and still was skeptical. We all have been victims of the embellished claims of manufacturers, right? I had already spend 3 Saturdays scrubbing the interior of my not-so-huge boat! The results angered me. My boat is constantly kept covered and is always wet inside from the kids and their skiing. Long story short, it has never looked this good since I have owned it.
ProsUnbelievably easy to use. Just spray on and WATCH the mold disappear.
By Wes
Table Rock Lake MO
October 19, 2018
Works Great !
Nothing I have tried before works like this. Almost effortlessly made seats look new again.
By Sabrina
Birch Villa resort Cass Lake
October 19, 2018
I own a resort and have several rental boats, these boats are used almost everyday throughout the summer. The mildew is horrendous by summers end. So believe me when I say I have never found a product like Marine 31 mildew remover. This is my second year I have used this product on our pontoon boats. I just spray it on and go back and wipe down. It does all the work for me.
ProsEasy to use and fast acting
ConsStrong smell
By Gilbert Von Vogt
October 18, 2018
Easy and quick
Just sprayed it on - let it sit for a while and wipe - and the stains are gone!
By Joe
Santa Rosa Beach Florida
October 17, 2018
Excellent product
Excellent product best that I have found for cleaning mildew. Only wish I could find it close by.
By Riney
October 14, 2018
Too Easy
Product is incredible and so easy to use. My mildew was very bad and I was very skeptical, but after researching the product, I had to give it a try. Glad I did. Pontoon boat cushions look new!!!
By Kathy
October 11, 2018
Worth EVERY Penny - Order 1 to use and 1 to save for later
This stuff just flat works. After trying all the brands and nothing worked, including Mr. Clean Magic Erasers and 3M Mildew cleaner and scrubbing. I found a link to this online and ordered 2 bottles. We tried a hidden spot. My husband said, that will never come out. Wrong. Even the spots that were the worst, but hidden are gone. The seats are clean, clean, clean. No harm to anything. Thank you. We thought they were a lost cause. We used 1 bottle and now have a spare in the boat house, just in case.
ProsWorks as described. No harm to seats or surrounding carpet. They look brand new.
By Ron
Charleston S.C.
October 7, 2018
Very Good
The online videos show people spraying it on and wiping it right off and Presto! Completely clean. Nope. Gotta let it sit for a while then scrub pretty hard with a stiff brush. After a while you get the mold and mildew off but it still takes work. Also, the smell of this stuff is Strong! I think it is probably the better of the products offered out there...
By Cheryl Martin
Cheryl, Irwin, PA
October 6, 2018
Miracle Product
I never take the time to write reviews. However, this product certainly deserves one. My husband and I have tried every mildew remover product out there. Nothing worked. I came across this site online and read other's reviews. Decided to try one last product before giving up. This is truly a miracle product. One piece of advice---wait the 3-5 minutes after spraying. then use either a scrub brush or scrub pad. You will not believe the difference. to all you boaters---this is definitely worth the money. I just ordered the gallon refill jug to have on hand in the future. If your boat interior is bad with mildew, just order the gallon jug. You will use it up fast. It doesn't take off every little spec, but close to it.
ProsIt works!!!
By Connie Kevan
Danbury Wisconsin
October 5, 2018
Marine 31 Mildew remover
Most amazing product I ever bought. Tried everytning to clean the seats on an old neglected pontoon we bought last summer and nothing worked. I ordered Marine 31 Mildew Remover and the mildew disappeared like magic after spraying it on the seats. They look almost new. I’m going to order the rest of their products to keep the seats looking new and to preserve them.
By Keith
Bridgeville, DE
October 3, 2018
Absolutely Unbelievable
I tried 2 other products to remove mold / mildew from my golf car seats, they didn’t work. I even used a “power brush” with these products thinking this would break it up. Not so lucky. Started looking online for replacement covers / seats to resolve my issue. My wife was also searching online for another type of cleaner when she came across a video of someone using Marine 31. In the video, it was hard to believe it was so easy to use and worked so well. We ordered some and It worked better than one could ever imagine. Sprayed it on, let it set for 3 minutes and wiped it off. UNBELIEVABLE, the mold / mildew was completely gone. I was amazed ! This product absolutely does what it claims to do, remove mold / mildew. I have already recommended it to a friend of ours who owns a marina, sending him a video of the results. Thanks Marine 31 for saving us both time and money.
By Lana
September 30, 2018
We only ordered one bottle to make sure we were not wasting money on something that didn't work, because we had tried everything already. We will be ordering more, this stuff is amazing and it does everything it says. Our boat seats look like we replaced them with new ones, but all we did was use marine 31.
Lansing, MI
September 28, 2018
Marine 31
I purchased a large bottle of Marine 31 in June but did not use it until today Sept 28 as I winterize the boat. I am totally shocked at how fast this product made the mildew disappear. Four minutes I would guess with no scrubbing...I was floored. I spent the whole summer apologizing to my lake guests regarding this black mildew on my bimini top. I considered purchasing a replacement fabric for my bimini top this fall. Wow, wow and wow I'm overjoyed!

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