How To Clean A Dirty Boat

Paul Luisi
by Paul

Giving a dirty boat a thorough cleaning can be done with some hard scrubbing and simple washing.

To get started, you'll need a power washer, boat soap, hot water, bilge cleaner and other marine cleaners to tackle that stubborn, hard-to-remove dirt.

Power washing a boat with warm water will also help with the grimiest dirt and removing sea salt.

To clean a boat:

  1. Power wash the exterior to remove excess dirt
  2. Scrub hard surfaces with bristle brush and marine soap
  3. Rinse with hose
  4. Vacuum the seats and wash them with warm water
  5. Vacuum marine carpet and scrub carpet with carpet stain remover
  6. Dry entire boat with towels and microfiber cloth

After following the cleaning instructions, the boat will look clean and like new.

Cleaning The Exterior Of A Boat

Procedures for cleaning the exterior of a boat involves:

  • Power washing the boat hull
  • Cleaning the boat deck
  • Washing and removing stains from the boat canvas
  • Scrubbing the exterior hard and flat surfaces

Cleaning The Boat Hull

Washing and cleaning the dirty boat hull can be done in two ways, cleaning the hull in the water or cleaning the hull outside of the water

The easiest way to clean the hull is when the boat is out of the water.

When boat is out of the water

You'll need a pressure washer, warm water, a cleaning cloth, a scrubbing brush, some marine soap and hull cleaner to get started.

To clean a boat hull when the boat is out of the water, simply follow the steps:

  1. High Pressure Rinse: Use the power washer to perform a high pressure rinse of the hull. This will help remove any bulky and heavy dirt.
  2. Scrub The Hull With Soap & Hull Cleaner: Use a brush to scrub those tougher areas with soap and marine hull cleaner products. (Be careful not to remove paint)
  3. Power Wash The Hull With Warm Water: Once you've scrubbed the entire hull, use the power washer with warm water to blast away all the dirty spots.
  4. Dry The Hull With Marine Cloth/Towel: Use a cloth or towel to dry the hull and remove the final bits of dirt and scum lines.

Once you follow the steps, the hull will be spotless and ready to go.

When boat is in the water

You'll need underwater cleaning tools like a hull scraper or a rotary brush to help wash and clean the hull.

You'll also need marine grade environmentally friendly cleaning liquid.

To clean the hull when boat is still in the water: 

  1. Use Rotary Brush To Remove Heavy Dirt: Use this to scrub the hull and remove dirt. This will help with trapped dirt and can be done from the dock.
  2. Remove remaining dirt with scrub: Use a scrub to manually scrub the hull from the water. Use marine grade and environmentally friendly cleaning products for this.

These two steps will help tackle any dirt and mildew build up in and around the hull area.

Read cleaning a boat hull in the water guide for more methods of getting rid of dirt on the hull in the water.

Cleaning the hull can be done either when a boat is in the water or outside the water. Use warm water, a pressure washer, a rotary brush and marine grade cleaning products to scrub and remove dirt.

Cleaning The Boat Deck

When cleaning a boat deck, you'll need a scrub, warm water, soap and deck cleaner.

Deck cleaner will help protect from future stains.

To clean a boat deck: 

  1. Scrub the deck with soap: Simply get some hot water and soap and start scrubbing off the tougher and harder to clean dirt on the deck.
  2. Scrub the deck with deck cleaner: Wet the deck with warm water again. Apply the deck cleaner to the the surface. Use a deck brush to wash out grime and protect from future stains.
  3. Dry the deck with marine cloth/towel: Use a cloth or towel to dry the deck.

Once you've followed the steps, the boat's deck should be clean and spotless.

It'll also have a protective coating to help prevent future stains.

Boat decks are can be made of different surfaces from teak to non-skid.

Teak deck cleaning and non-skid deck cleaning typically require different cleaning products when washing them but the process of washing remains the same.

It's just the products that are different.

Scrub the deck with warm water, deck cleaner and a deck brush. The deck cleaner will protect against future stains.

Cleaning The Interior Of A Boat

Procedures for cleaning the interior of a boat involves:

  • Cleaning the boat seats
  • Washing the engine bay
  • Cleaning the bilge
  • Scrubbing marine carpet

Cleaning The Boat Seats

To clean the boat seats, you'll need a vacuum, warm water, a scrub or brush, marine vinyl cleaner, soap and a cloth.

The steps for cleaning the boat seats:

  1. Vacuum the hard to get surfaces: Use a vacuum to get the dirt in the tricky spots.
  2. Pour warm water and soap over the seats: Use warm water and soap to brush and scrub the dirty areas.
  3. Dry seats with microfiber cloth: Use a microfiber cloth to dry the seats and remove mold, dirt or stains.
  4. Spray seats with UV protective spray: Use a UV protective spray to help with sun damage and prevent seat cracking.

The boat seats will look new once you remove mold and dirt. Read the how to clean boat seats guide for more methods on washing your seats.

Vacuum the boat seats to remove trapped dirt. Then scrub the seats with warm water and soap. Dry with a microfiber cloth and spray UV protective spray to prevent sun damage.

Cleaning The Boat Engine

These cleaning instructions apply to outboard motors. You'll need soap, warm water and boat salt remover cleaner.

To clean the boat engine: 

  1. Seal fuel and oil containers: Make sure the fuel and oil containers are closed so no water gets into them.
  2. Apply warm water and soap: Use warm water and soap to brush and scrub the dirty areas around the engine.
  3. Apply boat de salt cleaner: Use a boat de salt cleaner to help remove sea salt from the engine and engine bay.
  4. Dry with a cloth: Dry the engine off when finished washing to remove those stubborn stains and build up of dirt.

Once you follow the steps, the engine should be clean and protected from the corrosive sea salt.

If you plan on cleaning the engine in more detail, read how to clean boat fuel tank for information on how to do it safely.

Use warm water, marine soap and salt remover cleaner to clean and remove dirt and sea salt from the engine and engine bay. Dry off with a cloth.

Cleaning The Boat Bilge

To clean the boat bilge, you'll need warm water, a cleaning brush, bilge cleaner and a towel or cloth.

The steps for cleaning the bilge:

  1. Put soap in the bilge with warm water: Mix soup with warm water in the bilge.
  2. Scrub the dirty areas with a cloth: Use a cloth to scrub the dirty areas.
  3. Pump out the dirty water: Pump out the water in a safe and legally compliant way.
  4. Pour water into bilge with bilge cleaner: Mix water with the bilge cleaner and let it sit for at least one hour.
  5. Drain the bilge: Drain the bilge of all fluids and dry it off with a cloth.

Once followed, the boat bilge will be free of dirt, stains, mold or any bad smells.

Read how to clean a boat bilge for more methods on washing the bilge.

Use warm water, a scrub and bilge cleaner to wash the bilge. Let the cleaner sit in the bilge for an hour before draining it and drying it with a cloth.

Products To Use When Cleaning Boat

When cleaning a boat, products to use include:

  • A Pressure Washer
  • Bilge Cleaner
  • Hull Cleaner
  • Boat Seat Cleaner
  • Deck Cleaner
  • Marine Carpet Cleaner
  • Boat Polish
  • Boat Engine Cleaner

These products are enough to completely clean the boat interior and exterior.

Our list of the best boat cleaning products will also assist with cleaning the boat.

The Bottom Line

Whether cleaning the interior or exterior of the vessel, it's important to have the right cleaning products.

Most areas on a boat can be washed and cleaned with just some warm water, soap, boat polish for waxing, a brush and a cloth or drying towel.

As a result, the vessel will be spotless inside and out.