How to Clean Boat Cushions and Seats

The saltwater environment is harsh on seats and cushions, here are top tips to keep them clean and mold- and mildew-free.
Sunbrella canvass cushions
Many boat seats and cushions are upholstered with the popular Sunbrella canvas, which can be cleaned with soapy water as well as canvass-specific cleaners. Sunbrella

Soft goods take a serious beating on boats, and since they’re often exposed to weather and UV rays, boat cushions and seats, in particular, usually have a limited lifespan. After just a few years, boat seats often begin looking dirty, weathered and worn. If you work hard to take care of them from day one, they may last for up to a decade or possibly even more. However, at some point boat seats can have mold or mildew, and knowing how to clean boat cushions and seats so they look like new can give them a new lease on life.

 How to Clean Vinyl Boat Cushions and Seats on a Regular Basis

The majority of the boat cushions and seats are made with marine vinyl. As mentioned earlier, the key to longevity in any type of boat seat is keeping it clean at the outset. With vinyl, this means that after each and every time you use the boat it should be washed down with gentle boat soap and a soft rag, then rinsed and allowed to air-dry. If the boat or seats are kept covered—an excellent way to prevent weathering and UV damage—the cover should have adequate ventilation so moisture doesn’t get trapped inside and encourage microbe growth.

Mildew on boat seat
It is possible to breathe new life into mildew-stained seats and cushions with cleaners and elbow grease. Courtesy Lenny Rudow

Avoid using harsh scrub brushes and cleaners, which can eat away manufacturer-applied, antimicrobial treatments on seats. These treatments help hold mold and mildew at bay for years, but can be scrubbed away with overly vigorous cleanings. Instead, be gentle and thorough. If you leave contaminants behind, it can give microbes a foothold to grow on and from there they spread into the vinyl itself. 

Mold and mildew will appear at some point, and you’ll need to attack this cleaning job with a bit more strength. Now’s the time to use a dedicated vinyl cleaner/restorer, which rejuvenates the seat’s surfaces. Eventually, even that will have little effect, and you’ll have to decide to either replace the seats or use the nuclear option: bleach. Bleach is caustic and will indeed wipe out that mold and mildew, but it will also attack the vinyl, and especially the threads used to hold it together. Recognize that using it will probably gain you just a season or two before the materials crack, split and fall apart.

Rub ‘n Restore before and after
Badly mildewed boat seats and cushions require a stronger alternative. In this case, a dedicated cleaner/restorer like Rub ‘n Restore will help get the job done. Rub ‘n Restore

Note: when you finally decide to replace boat cushions and seats, don’t try to have the same foam re-wrapped and reused. By now, mold and mildew will likely be living in the cushions as well as on the surfaces. If you reuse the foam, it will grow from the inside out and quickly contaminate the new materials.

How to Clean Silicon Boat Cushions and Seats

Some newer, high-end boat cushions and seats are made of silicon rather than vinyl, which has a softer feel, resists mold and mildew growth better and has more stain-resistance. Once again, the key to longevity is keeping it clean from the get-go. Also similar to vinyl care, soapy water and a soft cloth are generally needed to remove contaminants and stains. As the material ages and collects imperfections, however, the more cleaning measures differ. In some cases, isopropyl alcohol may do the job, but it must be immediately and thoroughly rinsed away. Certain specific cleaners and stain removers (generally those designed for cleaning vinyl) can be helpful, however, some other cleaners can cause staining or bulges in the silicon. It’s critical to go to the manufacturer’s website and look for a listing of approved cleaners before trying anything. The manufacturer will have already tested a wide range of products and ranked or rated them as safe or unsafe for use.

Sportsman Open 352 upholstery
Many modern boats, like this Sportsman Open 352, have silicon upholstery rather than vinyl, which can require different cleaning agents. Sportsman Boats

How to Clean Canvas Boat Cushions and Seats

Sometimes you’ll find boat cushions and seats upholstered in canvas fabrics. These can be cleaned like other pieces of canvas aboard your boat: first try soapy water and a sponge, and if that doesn’t do the trick, try agitating stains gently with a soft-bristle brush. If a stronger cleaner is necessary, use a dedicated canvas cleaner. The popular outdoor canvas manufacturer Sunbrella, for example, makes its own specific Sunbrella Clean Multipurpose Fabric Cleaner. They also have a dedicated cleaner specifically for oil-based staining, Sunbrella Extract Oil Based Stain Remover.

To level up the cleaning in many cases, remove the canvas cover from the cushion or furniture and soak it in soapy, lukewarm water prior to gently scrubbing at the stain, mold or mildew. If that doesn’t do the trick, try machine-washing the canvas in cold water on a delicate cycle with laundry detergent. If the staining is severe, try adding a bit of bleach, but again, note that this will be harsh on the material and shorten its overall lifespan.

We can’t stress enough, keeping the boat cushions and seats clean on a regular basis is the best practice. The battle to remove established mold, mildew, or stains from the material is much tougher than preventing it from gaining a foothold in the first place.