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How to Pressure Wash a Boat

While many people view boat ownership as a great investment into creating priceless memories and experiences, there’s a side of it that isn’t as glamorous. Not many people really give consideration to all the work that’s involved with care and maintenance. Well, at least for those just starting to look for a boat to buy.

Cleaning your boat is an important task to check off after every use. You can not only avoid costly repairs, but you can also prolong the life of the boat. Let me recommend a pressure washer as the tool of choice when it comes to cleaning your boat. With a pressure washer, you can quickly loosen dirt and grime, apply and spray biodegradable marine soap onto the boat’s surfaces and rinse off accumulated marine buildup.

Imagine doing all that by hand. Out in the sun and on your knees scrubbing here and there. Sounds labor intensive and time consuming doesn’t it. With a pressure washer it doesn’t have to be. Let me go further into detail about what you’ll need to do to get started and what steps are required to complete the job.


As with any cleaning job, there’s some prep work that needs to be done. These tasks mostly involve getting ready the area and choosing the right tools and instruments to use. Obviously, you’ll need a pressure washer for this project. In addition to that, prepare soap, pressure washer nozzles and attachments, and lastly marine wax.

Prepare the area

This step is obvious so I won’t talk too much here. Make sure everything is put away. Items such as life vests, fishing poles, seat cushions and random cans should be cleared away so that you can maximize the area that you’re cleaning. 

Also, close any doors, windows or portholes. You don’t want water to be ruining the insides of your boat.

Keep these two points in mind. You always run the risk of damaging things if you’re not careful with the powerful blasts of water that come from the washer. You also run the risk of injuring yourself if you’re not careful with your footing while pressure washing.

Pick the right soap

The first thing is to make sure you have the right soap or detergent for your boat. Besides reading the owner manual for your pressure washer, you want to make sure that you get one that will not damage the hull of your boat either. 

Usually, a biodegradable one should be sufficient, but make sure that it is marine safe as well. Not just for the preservation of the local ecosystem, but also for the preservation of your boat as well. Wouldn’t do much good to wash your boat to keep it in like new condition if the soap you use will damage it in the process. 

Contacting someone at your local boat shop would probably be best as a local big box store or even home improvement store may not be fully knowledgeable about exactly what you need. Once you know what to use, then finding a better price at a different store would be prudent. 

Set aside these two washer nozzles

There will be two nozzles that you’ll be using. Pressure washer nozzles are universally color coded, so don’t worry about this part. Set aside the black and green nozzles for use.

You’ll start off with the black nozzle, also commonly referred to as the soaker nozzle. It’s used to apply detergent on surfaces. What makes it an ideal nozzle for soap application is its design. 

The black nozzle utilizes a 65 degree spray pattern, which is wide and great covering large surfaces with soap. It also discharges the lowest water pressure. Once the detergent is applied, you don’t want the soap to be immediately blasted off. Let it coat and do its job.

Copyright protected content owner: and was initially posted on September 4, 2019.

The green nozzle utilizes a 25 degree spray pattern. This is accomplished with a smaller nozzle orifice. The effect is a more focused and concentrated water spray, which is good for rinsing. The increased water pressure is able to lift and wash away stubborn spots and stains.

Prepare misc. attachments

Washer attachments can make life easier by helping you quickly finish the job. Like these two that I’m going to recommend. Give them a try.

First is the scrub brush attachment, which will save you from having to really scrub at getting and dirt, debris or algae off of your boat. The scrub brush attachment has a rotating head which will make the job so much easier for you.

The second attachment needed is an extender. This is used either with the scrub brush attachment or alone to make sure that you can reach under the boat without killing your back or up near the top of your boat, depending on the make and model of your boat. 

Have marine wax ready

While this has nothing to do with pressuring washing your boat, it is vital for good maintenance and is a vital part of boat ownership. The best time to apply the wax is a day or two after you have washed it, giving it time to dry completely first. Once a year you will want to wax as much of the boat as you can, including inside on the seats and nearly every visible surface (minus anything that is non-skid as it will defeat the purpose of it).

Using a wax that is approved for marine use (usually called marine wax or hull wax), to protect your boat from sun or water damage, make sure to coat the full hull from top to bottom. 

Cleaning Your Boat

Now that preparations have been made, the next step is the actual pressure washing on your boat. While the hull is your main objective, you will want to clean the deck and the trailer as well, along with the motor, but each of these areas is handled differently. 

The Hull

Cleaning the hull will be the longest part of the pressure washing, but is also the simplest. The basic steps are:

  1. Rinse off loose dirt
  2. Apply soap
  3. Keep soap wet
  4. Rinse and scrub
  5. Allow to dry
  6. Apply wax

Rinse off loose dirt

By taking the time to rinse off any loose dirt, you will not only make your soap more effective but can get into those little nooks and crannies that are hiding more grime. Start by spraying your boat, from top to bottom, to get off any loose dirt. If you are using it in saltwater, this will also help to remove any remaining salt as well. 

By taking the time to make sure you get into all of the little crevices, you can help extend the lifetime of your boat. Since boats can also take on barnacles and algae, by doing a detailed rinse before applying the soap, you should be able to remove most of the loose stuff before you actually wash your boat.

Apply soap

Using a biodegradable soap, the one you previously researched and purchased specifically for your boat, you want to use a pressure washer to apply the soap in small sections. Working from bottom to top, to make sure you don’t miss any parts and to prevent streaking, work in small sections to reduce movement and get the job done quicker. 

Keep soap wet

Once you have gone all the way around you need to make sure that the soap stays wet. This is where a black nozzle would be the perfect one to use as it would provide a gentle spray that will keep the soap wet and active without rinsing it off. 

Rinse and scrub

Using the scrub brush attachment, you first want to make sure that you have rinsed all of the soap out of the pressure washer, so just a quick 10 – 15 second spray on the ground should ensure all of the soap is out.

Next, starting from the top this time, you want to work in small sections, going from side to side, rinsing the soap off and scrubbing, gently, where needed. The objective is to remove dirt and grime from your hull, not that paint or varnish. 

Allow to dry completely

This is going to be the longest part of washing the boat which is waiting for a couple of days allowing everything to dry out completely. The wax is not effective on a wet surface, and it would just be a waste of time to try to apply wax to a wet section of your hull. 

Apply the wax

The last part is applying the wax. If you are getting ready to store your boat for the season, then you may want to apply wax to as much of it as you can. If you are lucky enough to live in an area that you can use your boat year round, then you may want to pick a time of the year, or even wax the full boat two or three times a year, since it would be in use more often. 

Paying special attention to the hull, you want to try to make sure as much of the hull is covered, especially where it would be in contact with the water. 

The Deck

This may be a big job or small, depending on the size of your boat. You want to make sure that you can remove any water that gets onto your deck to reduce the risk of water damage as well. 

For small boats pressure washing the deck may be a few minutes, and the hardest part may just be climbing into and out of the boat before and after, respectively. 

For larger boats, however, it may be a bit more complicated. Some larger boats have specialized wood, like teak, which can easily be damaged. They can also have a varnish coating that could come off if too much pressure is used.

Copyright article owner is for this article. This post was first published on September 4, 2019.

You also need to be careful with things like windshields. Not only are they vulnerable to being easily broken, but oftentimes they have a plastic coating that can be scratched very easily, even by a pressure washer. 

The Motor

Keeping the motor clean and in top condition is vital to the enjoyment of your boat. You need to gently spray off any dirt or debris that got onto the motor. Make sure if you get any soap on the motor that it gets rinsed off as the soap could damage it, making for a higher expense. 

The Trailer

This is probably the most neglected part when people decide to pressure wash their boats. Trailers get wet from going in and out of the water and with the water from the boat dripping on it, it can actually stay wet longer. 

If at any point, you have to drive down a dirt road or even a dirty one, it can collect a lot of dirt on the underside, especially in the wheel wells and near the tires. These areas will need to be washed as well to remove the debris that it may have collected. 

While you can use more pressure on the wheel wells and underneath the trailer, care does need to be taken around the tires as too much pressure could damage them or even pop one. 

ReadyToDIY is the owner of this article. This post was published on September 4, 2019.

Extra Tips

A few tips and tricks may help keep more than just your boat in pristine condition. 

  • Many people have decals on their boats, whether it is for aesthetic purposes or legal ones, you will want to take extra care that you do not accidentally pressure wash these off with the dirt.  With decals start at the middle and work towards the outside. Check after you wash it to make sure you did not lift it. 
  • Use low pressure on your pressure washer for rinsing off the soap. At this point, you are not trying to wash off the dirt and grime, but just rinse it off. So try a wide angle fan spray and could even use the white nozzle which is set at 40 degrees. This is safe for most windows as well, so it would be safe for spraying the soap off. 
  • When rinsing off the soap take a step back to reduce the pressure as well. If you think of the hull of your boat as an eggshell, you don’t need a lot of pressure to rinse it. Standing back a bit may remind you to go easy on the pressure. 
  • Try to rinse a section three or four times, just to ensure all of the soap and dirt is off. 
  • Try to do everything in smaller sections; three to four foot sections is best. This will ensure that everything is washed and rinsed properly and you can give more attention to a stubborn area if need be. 
  • Using a medium duty pressure washer should be sufficient as you need at least 2,000 PSI (Pounds per Square Inch)but don’t want to go above 2,500 PSI. You need to have a high enough pressure to get into the cracks, but not damage your boat. Your purpose is to wash your boat, not take off the paint or varnish. 
  • Try not to hit your windows or windshield with the pressure washer. Windows can break pretty easy, and windshields tend to have a plastic covering. It is best to use typical glass cleaner for these instead. Alternatively, some people do use newspaper and ammonia for cleaning glass. 
  • Try to limit the exposure of chemicals, such as the detergent, to 15 minutes or less even if you need to wash in smaller sections to do this. Chemicals, even soap, can damage the hull of your boat, so limiting the time it is in contact with your boat may help lengthen the lifetime of it. 
  • If streaks bother you, you can use a chamois cloth to dry off the hull of your boat, especially if you are planning to buff and wax your boat. A chamois cloth will allow for a streak free surface and is just that little extra attention to detail that can show in the final shine. 
  • Be careful what nozzle tips you use as they could damage your hull. Red tip (0 degree) are very strong pressure, even for a lower PSI washer. These could end up etching the paint or protective coating right off. Yellow tip (15 degrees) are more for stripping paint and varnish off, so unless you are planning to refinish your boat, best to avoid these too. 
  • The carpeting in your boat can take some serious abuse and result in damage too. Using a pressure washer to clean it can bring new life to your carpet. If you can dry it using a wet/dry vac afterward, this will help pull up even more dirt as well. 
  • Buffing can help enhance the shine on your boat. By buffing the boat before you wax it, it will help to bring that new boat look back. This can be done by hand or with a rotary buffer to bring the best shine you can to your boat. Buffing also helps to remove any oxidation that may have occurred through use. 
  • When washing the motor, make sure to pay attention to the propellor. Cleaning is the perfect time to assess for damage and make sure that you are doing everything you can to ensure the longevity of your motor. By keeping your propellor clean, it can help to reduce fuel costs as well.