How to Clean a Boat: Cleaning Basics

Keeping your boat clean and looking good isn’t just a matter of pure vanity, it’s also an important part of basic boat maintenance—knowing how to clean a boat is imperative for any boat owner. It extends the useful lifespan of materials that are exposed to the environment, improves functionality in many cases, and if you keep it looking good you can sell your boat for more when the time comes to upgrade. Ready to get scrubbing? Let’s look at how to clean the different pieces and parts of your boat inside, and out.

Effective boat cleaning involves focusing on these specific areas:

  • Interior surfaces (carpet, fiberglass, vinyl, cushions, head)
  • Exterior surfaces (hull, gel-coat, canvas)
  • Engine
  • Teak

How to Clean a Boat Interior

Whether you have a big cabin cruiser or a bowrider with a head compartment, each part of the boat’s interior has its own needs. Items to consider include:

  • Marine Carpet
  • Non-slip Fiberglass
  • Vinyl
  • Cushions
  • Heads

Marine Carpet

Marine carpet is found in many cabins and may also be inside the cockpits or head compartments of some smaller boats. Some types of boats, like bass boats, are commonly carpeted inside from bow to stern. In either case, the best way to clean it is to first use a vacuum to remove loose dirt, then give it an old-fashioned scrub-down with a stiff-bristle brush, soap, and water. Trailer boats can be parked on an incline so most of the water drains away vi gravity, but on larger boats and inside cabins you may need to suck up remaining water with a wet-vac, then speed drying by running the air-conditioning and/or fans.

Non-slip Fiberglass

Non-slip Fiberglass Fiberglass with molded-in non-skid is found in and on boats of all sorts both inside and out. But it can’t be treated like other fiberglass parts, because wax would make it slippery and defeat the purpose of having a non-skid surface in the first place. As you might expect this process will also start with a hard scrub with a stiff bristle brush, soap, and water. Tough stains can be attacked with a cleaner that has a bit of bleach, like Soft Scrub, but minimize its use and make sure it’s rinsed away thoroughly because bleach is tough on fiberglass surfaces. Then, give it a treatment with a specialized non-skid treatment like Star Brite Non-Skid Deck Wax or Woody Wax. Technically these products aren’t “wax” in the traditional sense, but are protectants with polymers that help shine and protect the non-skid without making it slippery – think of them like suntan lotion for your boat’s nonskid.


There’s lots of vinyl found on boats of all types, especially those designed with gobs of seating for cruising or watersports. Modern marine vinyls come from the factory treated with anti-microbials, and these are your best long-term defense against mold and mildew, so stay away from harsh chemical cleaners that can remove them. Instead, keep vinyls as clean as possible and give them a washdown with gentle soapy water and a soft rag every time you use the boat. Tough stains should be attacked with a dedicated marine vinyl cleaner, and followed up with a thorough rinse and then an application of a vinyl protectant.


Interior cushions can become musty over time, blemished by spills, and invaded by mildew. To clean them, first remove the covers and wash them in cold water. Most (non-vinyl) cushion covers can be machine-washed, but don’t wash them in hot water and toss them in the dryer or shrinkage is a serious danger. As for the foam, first sprinkle baking soda on both sides of the cushion, let it sit for a few hours, then shake it off. Then mist the foam with a 50-50 mix of vinegar and water. Place the cushion in a well-ventilated area for a few days until the smell of the vinegar goes away. Then spray them down with a hose, squeeze the water out, and spray them again. It usually takes several soakings to get all the grime out. After a final squeeze, let them air-dry completely before putting he covers back on.


Marine heads can be cleaned more or less like the toilets at home, but cleaning the lines where scale and calcium deposits can collect is a different story. The solution: once a month, run a few cups of white vinegar through the lines.

how to clean a boat exterior

How to Clean a Boat Exterior

Okay—the inside’s all set. Now, let’s take a look at how to clean the boat’s exterior. Items to address include:

  • Hull and gel-coat surfaces
  • Hull bottoms
  • Canvas and Clear Canvas (Isinglass)
  • Engines
  • Teak

Hull and Gel-Coat Surfaces

Hullsides and other smooth gel-coated surfaces need serious protection and maintenance to stay shiny and avoid oxidation. This starts with a base coat of two layers of paste wax, each and every spring. Monthly, give the boat some extra shine by applying a liquid carnauba wax. Then, after each and every use wash the boat down with a boat soap that contains some liquid wax (usually called a “wash ‘n wax” soap).

Hull Bottom

If your boat is kept on a trailer or a lift, treat the hull bottom exactly as you treat other gel-coated areas. If the boat sits in a wet slip, however, you probably have had the bottom painted with an antifouling paint.

Canvas and Clear Canvas (Isinglass)

Boat canvas needs cleaning monthly, at least, to prevent staining and keep dirt from becoming embedded in the material. Simply hose it down, give it a gentle scrub with a soft-bristle brush and a mild soap like Woolit, and rinse it off. Every few years you may need to do a heavier cleaning. If it’s small enough, the canvas can be gently machine-washed with warm (under 120-degrees) water, a bit of soap, and two cups of baking soda. If this doesn’t do the trick (or if the piece of canvass is too large to fit into the washing machine) it’ll have to be scrubbed by hand. Some manufacturers recommend using a cup of bleach and a quarter-cup of soap mixed with a gallon of water, while others recommend a baking soda/soap mix. Refer to the manufacturer of your canvass, before taking this step.

When it comes to clear canvas, remember that there are several different types of clear canvas including polycarbonate, acrylic, and polyvinyl. Cleaning all of these begins with a gentle wash-down with soapy water and a non-abrasive sponge or microfiber cloth, each and every time the boat comes back to the dock. Follow the wash up by wiping the curtains with a squeegee or chamois, to remove water droplets and prevent them from drying and leaving behind water spots. After that stage, however, each manufacturer has its own recommendation for polishes and protectants. Read Enclosure Disclosures to learn more about caring for canvass, clear canvass boat curtains, and the ins and outs of the different types.


Boat engines need regular cleaning inside and out, no matter whether you have an inboard or an outboard powering your boat. In the case of outboard engines, this starts by waxing the cowl and exterior, then washing them down with soap and water after every use. These surfaces are very similar to automotive finishes, so treat them just as you treat your car. Use microfiber cloths or wash mitts, and never hit an outboard cowl with an abrasive bristle brush.

What about under the cowl, or the engine itself in the case of an inboard? It’s important to regularly wipe away accumulated dirt and grime. Remember, however, that there are electrical wires and components that can be damaged by some cleaners and chemicals. So beyond a superficial wipe-down, it’s usually best to leave engine cleaning to a pro.


Simple scrub-downs with soapy water are the best way to regularly clean teak, but this will only get you by for so long. Depending on where you live and the air quality and UV intensity, your teak will eventually begin to blacken and look mottled. At this point, you’ll probably need to use an acid-based teak cleaner. There are mild one-part solutions as well as stronger two-part cleaners, and in both cases you’ll want to follow the manufacturer’s directions to a tee. One important note: remove the teak from the boat before using these cleaners. The acids in them will dull and damage gel coat, paint, and metals, and it’s impossible to effectively use these cleaners without getting some on the teak’s surrounding parts if you don’t remove it from the boat entirely before beginning.

Remember people, a clean boat is a happy boat. And now that you know how to clean a boat, your pride and joy should be grinning from gunwale to gunwale.