How To Clean A Boat (That Has Been Sitting)

Cleaning and caring for your boat is something you must do regularly It’s a lot like keeping your car clean. The more effort you put into keeping it clean and maintained the longer it will last.

To clean a boat that has been sitting for a long time you will need to focus your efforts on 5 different areas, see below:

  • Interior
  • Woodwork
  • Cushions
  • Engine
  • Boats Hull

Focusing on these 5 areas will make an old dirty boat look new! These steps can be applied to almost any type of boat as well. Keep reading to find out more about each area and how to clean it.

My favorite vinly boat seat protectant is this 303 Marine Aerospace Protectant. I use it on all of my outdoor cushions and hot tub cover. Trust me its great!!!

The Boats Interior

The boat’s interior is the first step in the boat cleaning process. Some people may start with the outside of the boat but I recommend working from the inside out. This way when you are done with the outside you will have a perfect view of a finished project. This will give a great feeling of satisfaction, trust me.

When it comes to cleaning the boat’s interior it will depend slightly on the type of boat and what is in the interior. I will use a 22 Catalina sailboat for my reference here since that is what I purchased a long time ago from someone’s backyard.

To clean the interior of the boat I followed the steps below.

  • Removed all objects from the interior of the boat – This consisted of removing old parts, cushions, trash, and tools.
  • Patched all cracks and holes – I patched a few spots from previous owners just to make sure everything was sealed up from the bilge area.
  • Cleaned all surfaces with soap and water – This was a very simple process. I used a bucket of water with Dawn dish soap. Dish soap works on everything. Any sponges and rags will help with this step as well. I do not recommend steel wool for scuff marks because it can scratch the surface. Try a magic eraser for scuff marks. They work very well.
  • Vacuum all areas – At the very end vacuum all areas of the interior. This will get any last dust particles on the boat.
  • Replace all items in the interior – This is the final step where you put everything back in the boat. Only put back what is needed. Over time we collect more and more stuff that we don’t need. This is the perfect time to reorganize your boat’s interior.

Try a magic eraser for scuff marks. They work very well.

These steps should help finish up the interior of your boat. They helped get my Catalina 22 looking very nice on the inside. Let us move to woodwork now!

Make sure you check your boat regularly so there are no surprises. Use my guide by click the image below!

Woodwork On The Boat

This will be specific to the type of boat you are working on. If you don’t have any wood on your boat feel free to skip to the next section.

I wanted to give woodworking its own section because it involves a lot of work to keep nice, especially if it’s teak.

For my Catalina 22, the first thing I did was remove all the wood from the interior. There is a column of wood down below that helps hold up the mast so I left that in there.

If you have a lot of wood on your boat, be sure to keep a list of where it all goes. My boat was quite small and very easy to put back from memory.

Depending on the type of wood and the condition it is in, will affect how you treat it. If you have teak, keep reading.

For my teak, I used a product called STAR BRITE TEAK KIT. You can buy the steps individually for around $20 but I bought the set to make it easier. Be sure to read the label before using this product.

To use the cleaner you will need a very soft brush or 3m pad. When cleaning teak you are scrubbing away small amounts of wood and you never want to take too much at a time. We only want to scrub away the dirt spots or stains.

Tips For Finishing Teak Wood On Your Boat

  • Before you apply new teak oil to your cleaned wood parts, make sure the wood is fully dry.
  • Read the label of all cleaning products before using them.
  • Never use a rough brush on teak. The softer it is the better.

Once you have completed cleaning and oiling your teak wood it is ready to be installed back on the boat.

Cleaning Cushions

When it comes to cleaning cushions, there is not too much you need to worry about. I am sure we have all cleaned some type of cushions at some point.

One easy way to prepare for cleaning your cushions is to find out the material they are made of. Vinyl will need to be treated differently than leather. Leather will need some good conditioner especially if it takes a lot of sunlight.

I recommend a mild soap and water rub down of seat cushions when cleaning them. If they have foam centers and non-waterproof cushion covers, I recommend taking the cushion covers off and cleaning them separately from the foam.

You never want your foam to get wet!

Another essential thing to remember about cushions is that sunlight will destroy the color.

I highly recommend products to protect them from the sun such as Scotchgard Water and Sun! This product is great for water and sun protection. It is intended for nylon-style cushions, not leather. I have used it for years and it is great!

If you have leather cushions, my sailboat had a leather cushioned v-berth, I recommend any leather conditioner and cleaner.

I personally use Chemical Guys Cleaner and Conditioner! It is perfect for your needs.

If you don’t have boat cushions and maybe you want some check out this article all about boat cushions.

Now that the interior of your boat and the cushions are clean, let’s look at the engine.

How To Clean A Boat Engine

When restoring an old boat, you will need to clean up the engine. All engines get grease and dirt piled up on themselves over time, but it is quite simple to clean.

The first thing to do is a basic check of all filters and lubricants. If any of these need to be changed or topped off, you will want to do it before cleaning the engine. After you have checked everything and it looks good, it is time to clean.

First, you need to spray your engine down with a degreaser, this one comes highly recommended.

Gunk Engine Cleaner

Once you spray it down let it sit for a few minutes and then it’s time to wipe down. If the engine is an outboard you might be able to spray it down with a low-pressure hose but if it’s an inboard you will have to wipe. It may take a lot of rags to get all the grease and dirt off.

After the degreaser, a mild soap and water compound to detail the engine will work great.

A clean engine is a happy engine!

The final part of the boat to clean is the biggest! The Hull!

The Boat’s Hull

The boat’s hull is the final part of cleaning a boat that has been sitting there for years. We do this last because once this is done, you will have a clear view of a fully detailed boat. There are a few different ways you can go about cleaning the hull and it will depend a lot on where the boat is stored.

Boats On Trailers

For boats that are on a trailer, you have a couple of different options. You can tow the boat to a car wash and wash it just like a car, or you can do it at home with your garden hose and car cleaning products.

Pressure washers can make things go much more quick and easy.

If you have a power washer be careful not to put too much pressure on delicate areas like around the port holes. Any boat hull cleaner will be good for scrubbing your boat in the driveway. If your powerwasher has a soap tank, then this will save you even more time.

The top deck of the boat can be cleaned with a basic scrub brush and boat hull cleaner. This will be accomplished much more often than cleaning the bottom of the boat. Get a good brush and a lot of hull cleaner since you will be doing it multiple times a year.

Boats On The Water

Boats on the water will be cleaned a little differently than the ones on the trailer. ObYouon’t be able to tow it to the car wash. This means you will be doing most work by hand. You may be able to plug in your power washer somewhere but doing it by hand won’t be that hard especially if you have your guests help you.

Your guests should help you clean if they want to keep getting free rides on your boat.

The hardest part of cleaning a boat on the water will be the part of the hull that is under the water line. This will require someone diving down and scrubbing the boat clean of barnacles and scum. Most people just snorkel down and do this when it’s nice and warm out.

You could always hire some kid at the marina if you didn’t want to do it yourself.

Any soft bristle brush or scrubbing sponge should be enough depending on how long the boat has been sitting there. If it has been on the water for years, it would be wise to pull it out and inspect the hull for damage. This would be the perfect time to clean it as well. If the paint is old and falling off, be careful scrubbing it, unless you are going to paint it anyways.

The top deck of the boat can be cleaned with a basic scrub brush and boat hull cleaner. If you are on salt water, you will be doing it a lot!

One important thing to remember, make sure your boat cleaner is biodegradable. We do not want to be polluting our lakes and oceans.

After you have finished cleaning the boat’s hull, your boat should be fully clean and restored.

8 Essential Tools For Cleaning A Boat

1. Boat Hull Cleaner

This product is great for cleaning the boat hull and deck.

2. Wood Teak Kit

If you have teak wood I strongly recommend this product. I have used it before and it worked great!

3. Cushion UV And Water Protectant

If your cushions will be in the sun all day, make sure you protect them from the sun’s UV rays.

4. Leather Cushion Cleaner And Conditioner

If you have leather seats you will need to take extra special care of them.

5. Boat Engine Cleaner

If you have an outboard or an inboard motor, you will need to clean it at some point.

6. Deck Brush

A deck brush is essential to have. Think about how long you need it to be before buying it.

7. Magic Erasers

These are the best things for those hard-to-remove scuff marks. Trust me!

8. Marine Polish Kit

If you have a type of boat you want to polish and show off its perfect paint job, then waxing will be necessary. For sailboats, I do not see the need.

Final Thoughts

This article was all about cleaning your boat. If the boat had been sitting for a few years or a few months the process should be the same. The only thing that will change is your elbow grease. The 5 areas mentioned above should cover all aspects of your boat. I recommend starting from the inside and working your way out. The products I listed above are the very same ones I used for cleaning my boat and I hope they help you clean yours. Cheers!


Boatlifehq owner and author/editor of this article.

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