How To Clean Boat Exterior

Paul Stockdale Author Avatar
Written by Paul Stockdale | March 3, 2023
Boat Exterior Cleaning

Washing and cleaning the exterior of the boat will remove mildew, sludge, rust, stains and other dirt from the vessel.

The exterior boat surfaces that need to be cleaned include the boat canvas, hull, outboard engine (where applicable) and exterior hard surfaces including deck railings and fittings.

To clean the exterior of a boat:

  1. Clean the boat canvas with a brush and a biodegradable canvas cleaner
  2. Clean the boat hull with a brush and hull cleaner
  3. Scrub the outboard boat engine bay with a scrub and engine cleaner
  4. Clean the exterior hard surfaces & fittings with a multi-surface marine cleaner

Follow these steps to have the boat exterior completely cleaned and looking like new.

1. Clean The Exterior Boat Canvas With A Boat Canvas Cleaner

The first step of cleaning the exterior of a boat is to clean the exterior boat canvas or bimini top.

The vessel's canvas can get dirty with mildew stains, grease, dirt and bird droppings. Weathering can cause the boat's canvas color to fade.

To clean the exterior boat canvas:

  1. Get a 16 oz. or more biodegradable boat canvas cleaner: Get a 16-ounce or more biodegradable cleaner that is compatible with canvas, nylon or other fabrics similar to your boat's canvas/bimini top material
  2. Dilute the canvas cleaner in a bucket of water: Mix the canvas cleaner with water and stir it well. For a 16oz. canvas cleaner, use a half gallon of water per one capsule of the cleaner
  3. Wet the dirty canvas with warm water: Pour warm water (under 120 degrees) all over the boat canvas surface in sections
  4. Apply the mixed water & canvas cleaner solution to the canvas top: Use a sponge or brush and apply the solution to the boat canvas. Scrub the dirty areas lightly. Work in small 2' x 2' areas for the best results. Repeat this process if the stains on the marine canvas are deep and harder to remove
  5. Rinse the canvas with fresh water: Use fresh water to rinse the soapy canvas and remove all the dirty water and soap
  6. Dry the boat canvas with a towel: Use a towel to lightly dry the boat canvas. This will speed up the drying process and help you to spot any missed stains or stains on the canvas

A boat owner should clean the boat canvas once per month.

Cleaning the boat canvas has benefits including it will keep dirt, mildew and stains away from the surface, it will improve the boat's aesthetics and it will prevent sun damage on the canvas area.

The products needed to clean the exterior boat canvas are a bucket, fresh water, 16oz. or more boat canvas cleaner and a sponge or brush.

The products to avoid when cleaning the exterior boat canvas are bleach or highly acidic cleaners as they can damage the canvas surface.

For most recreational boats, cleaning the boat canvas takes approximately 30 minutes to complete.

Summary
Use a biodegradable marine canvas cleaner and a brush to lightly scrub and remove dirt and stains from the canvas surface.

2. Clean The Exterior Boat Hull With A Hull Cleaner

The second step of cleaning the exterior of a boat is to clean the boat hull.

The boat hull area can have a buildup of dirt, grime, barnacles, oil, fish blood, scum, rust and grease that will need to be cleaned.

To clean the exterior boat hull:

  1. Remove the vessel from the seawater: Take the boat out of the seawater and place it on a boat towing trailer
  2. Pressure wash the hull to remove the excess dirt: Use a pressure washer and apply it to the hull to blast away the heavy and loose dirt buildup
  3. Get a 1-gallon hull cleaner: Get a 1-gallon great boat hull cleaner that is compatible with your boat hull surface i.e. a fiberglass hull cleaner for fiberglass hulls or an aluminum hull cleaner for aluminum boat hulls etc. A 1-gallon hull cleaner is better as there will be more cleaner available for removing all the dirt, especially on larger-length hulls
  4. Use a brush and apply the cleaner to the hull: Use a soft bristle brush and apply the cleaner to the hull in sections
  5. Let the cleaner soak on the hull for 2 minutes before scrubbing it: Let the hull cleaner soak on the hull surface for up to 2 minutes before scrubbing it with the brush
  6. Rinse the hull with the pressure washer: Use the pressure washer again to rinse the hull area from the soapy and dirty water
  7. Dry the hull with a towel: Use a towel to dry off the boat hull surface. this will help add a shine to the hull surface

Cleaning the boat hull has many benefits including it improves aesthetics, removes dirt and grime and it improves overall boat performance when all the heavy dirt is removed and the hull is washed.

Depending on the type of vessel, a boat hull should be cleaned between once every 3 months and once every 6 months.

There are different cleaning instructions for cleaning a boat hull in the water versus cleaning it out of the water, mainly you will need to use a boat hull scarper when the boat hull is underwater.

For extremely stubborn stains on the hull, the removing stains from the boat hull instructions should help.

The products used to clean the exterior boat hull include a pressure washer, a hull cleaner, a brush or sponge and a towel or cloth.

The products to avoid when cleaning the exterior boat hull include bleach or gasoline as they can cause the hull paint to crack or the color to fade.

Summary
Use a 1-gallon compatible hull cleaner and scrub the hull with a brush. Rinse it with a pressure washer and dry it off with a towel.

3. Clean The Exterior Outboard Boat Engine

The third step of cleaning the exterior of the boat is the clean the outboard motor.

The outboard boat motor can get dirty and see a buildup of grease, oil and corrosive seawater materials.

To clean the exterior outboard boat motor:

  1. Get a marine degreaser cleaner: Get a 16oz. or 22oz. marine degreaser. These cleaner ounces are more than enough to clean the outboard motor of a boat. The 1-gallon degreaser is better used for boats with multiple outboard motors and heavily used engines
  2. Wet the surfaces of the motor with fresh water: Use fresh water and a sponge and wet all the dirty surfaces on the outboard motor and the engine bay area
  3. Spray the degreaser onto the outboard motor in sections and let it soak: Spray the degreaser and wipe it evenly using a cloth into the boat motor's dirty surfaces. Let the degreaser soak on the surface for 1 to 3 minutes
  4. Scrub the surface with a sponge or brush: After letting it soak, scrub the dirty surface with a brush or sponge
  5. Rinse the soapy water away with fresh water: Use fresh water to rinse the scrubbed boat motor and rinse away all the soap

The benefits of cleaning the boat motor are it will remove grease, sludge and dirt from the engine and it will help keep the boat running smoothly.

An outboard boat motor should be cleaned once per month to ensure the boat motor is kept clean.

The products to use when cleaning an outboard motor are a marine degreaser, a sponge and a bucket of fresh water.

The products to avoid when cleaning an outboard motor are bleach or a household cleaner.

Bleach will damage the outboard motor surfaces and a household cleaner is not strong enough to remove the dirt from the motor.

Summary
Use a marine degreaser and a brush or scrub to remove grease and dirt from the boat motor.

4. Clean The Exterior Hard Surfaces & Fittings With A Multi-Surface Marine Cleaner

The fourth step of cleaning the exterior of a boat is to spray a multi-surface marine cleaner on the exterior hard surfaces and fittings.

The boat's exterior fittings and hard surfaces include metals, deck railings and exterior cockpit surfaces.

To clean the boat's exterior hard surfaces and fittings:

  • Get a 32 Oz. Or More Marine Multi-Surface Cleaner: Get a 32-ounce or more multi-surface marine cleaner. This cleaner can be used on all exterior surfaces and 32 ounces is more than enough to cover all the hard surfaces and fittings on most recreational boats
  • Spray the cleaner onto the dirt surface and let it soak: Spray the multi-surface cleaner onto the dirty hard surfaces and fittings and let it soak for up to 2 minutes
  • Wipe away with a cloth: Use a cloth to wipe away the spray and dirt from the boat's exterior surfaces and fittings
  • Reapply the spray if the dirt does not remove: For tricky stains and dirt, reapply the spray again to help remove the more stubborn dirt

The benefit of cleaning the boat's exterior hard surfaces and fittings include it removes dirt, stains and grease from the boat, it adds a shine to the surfaces and fittings and it improves the overall boat aesthetics.

The boat's exterior hard surfaces and fittings should be cleaned once per month.

The products used to clean a boat's exterior hard surfaces and fittings are a 32-ounce or more multi-surface marine cleaner, a bucket with fresh water and a sponge and cloth.

The products to avoid when cleaning a boat's exterior hard surfaces and fittings are bleach and gasoline as it will damage the surface and create a foul odor.

Summary
Spray a multi-surface cleaner onto the boat's exterior hard surfaces and fittings, let it soak for up to 2 minutes and then wipe it away with a cloth.

Products To Use When Cleaning Boat Exterior

The products used to clean a boat's exterior are:

  • Pressure Washer: A pressure washer is used to blast away the dirt on the hull area
  • Sponge, Towels, Microfiber Cloth: Sponges, towels and microfiber cloths are used for scrubbing, washing and drying the boat's exterior surfaces
  • Brush: A brush is used to scrub the extremely dirty areas of the boat's exterior
  • Bucket: A bucket is needed to store mixed cleaner and freshwater
  • Boat wax: A boat wax is needed to shine the marine exterior surfaces. Meguiar's Premium Marine Wax is the best marine wax to use to add a shine
  • 16 Oz. Or More Marine Canvas Cleaner: A 16-ounce or more marine canvas cleaner is needed for canvas cleaning
  • 16 oz. Exerior Boat Carpet Cleaner: A top boat carpet cleaner helps clean exterior boat carpets
  • 1-Gallon Marine Hull Cleaner: A 1-gallon hull cleaner is needed for cleaning and washing the boat's hull surface
  • 16 Oz. Or 22 Oz. Boat Engine Degreaser: A 16oz. or 22oz. marine engine degreaser is needed to clean the outboard boat motor
  • 32 oz. Boat Vinyl Cleaner: A top marine vinyl cleaner helps remove dirt from exterior vinyl surfaces
  • 32 Oz. Or More Multi-Surface Marine Cleaner: A 32-ounce or more multi-surface marine cleaner is used to clean the various exterior hard surfaces and fittings on a boat. 32 ounces is more than enough to clean most hard surfaces and fittings on most recreational vessels
  • Boat Buffer: A top buffer for a boat helps with waxing and shining the boat exterior

Our top boat cleaning products list will guide you on the exact products to use when cleaning the boat.

Products To Avoid When Cleaning Boat Exterior

The products to avoid when cleaning a boat's exterior are:

  • Bleach: Bleach can cause the boat's exterior painted surfaces to crack and cause the color to fade so it should be avoided when cleaning the exterior surfaces
  • Gasoline: Gasoline is highly flammable and has a foul odor so it should be avoided when cleaning the boat's exterior
  • Household cleaners: Household cleaners should be avoided when cleaning the boat's exterior as they are generally not compatible with some boat surfaces

Hire A Professional Boat Cleaning Company

An alternative option for cleaning the exterior of a boat is to hire a professional cleaning service.

To hire a professional boat cleaning company:

  • Contact your local marina
  • Check local Craigslist listings

The benefits of hiring a boat cleaning service are they will do all the work, they will save you time and hassle and they will know and apply to best cleaning products to your boat.

Hiring a boat cleaning company is best for those that do not enjoy DIY projects and would rather outsource the cleaning work.

Frequently Asked Questions About Exterior Boat Cleaning

Below are some common questions asked about cleaning a boat's exterior.

How Much Does It Cost To Clean A Boat's Exterior?

The cost to clean a boat's exterior is approximately $110. This price excludes the cost of a pressure washer.

How Often Should A Boat's Exterior Be Cleaned?

A boat's exterior should be cleaned an average of once per month.

How Long Does It Take To Clean A Boat's Exterior?

It takes a minimum of 1 hour to clean a boat's exterior surface. This time can vary substantially based on the size and the condition of the boat.

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