Best Hull Cleaner For Boats in 2020

Boat cleaning is a tiresome job if you don’t know how to do it properly! We tested and reviewed some of the best hull cleaner for boats that will save you time and lots of

Let’s face it!

Boat cleaning is a tiresome job if you don’t know how to do it properly!

We tested and reviewed some of the best hull cleaner for boats that will save you time and lots of energy.

You can choose between liquid, gels, and spray hull cleaners.

For heavy-duty cleaning go for the liquid. For safe and easy application, gel cleaners are perfect.

Let’s get started!


How we tested and compiled this review

We don’t own boats. So, that was a limitation behind reviewing these hull cleaners.

But as we talked with some of our marine enthusiast friends, we could get the results of the testing they did themselves.

So, a handful of research hours and expert opinions, we decided to review liquid and gel-based hull cleaners.

We took into consideration the following factors:

  • Power of cleaning
  • Ease of use
  • Safe on the marine environment

We couldn’t avoid some of the acid-based cleaners that might be problematic to the marine environment. But they still got into this list because of their heavy-duty cleaning power and popularity among experienced boat owners. 

Our Top picks and high performers

For deep deposit cleaning the Star Brite EZ-ON and EZ-ON is the best!

For safe and easy heavy stain removal the Star Brite Instant Hull Cleaner Gel Spray is the best!


Best hull cleaner for boats review

1. Star Brite Instant Hull Cleaner


Star Brite Instant Hull Cleaner
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Without any doubt, the Starbrite Instant Hull Cleaner is the best fiberglass hull cleaner in the market.

You ask any experienced marine guy, and you will almost always be recommended to use this product.

This is an oxalic acid boat cleaner, so the effects will be milder. It’s perfect for removing algae, fish blood,  yellowing, leaf stains, scum lines and other light cleaning jobs.

Don’t use it on a clean steel trailer because of the power of the solution.

You can buy a 128 oz gallon or a 32 oz quart. However, the 128 oz will save you a ton in the long run.

Keep in mind, you will need to wear gloves when using this cleanser. 

We didn’t find any issues of paint discoloration. However, avoid using it on the regular paint on the bottom of the boat.



  • Suitable for light cleaning of the hull
  • Friendly on hull paint
  • Will work on aluminum boats


  • Not powerful enough for zebra mussels or crusty jobs


Final verdict

The Star Brite Instant is a US-made hull cleaner. This is perfect for using before you do a boat polishing job. Fiberglass hulls need a milder touch, so this product will deliver exactly what you want.

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2. Star Brite EZ-ON EZ-OFF Hull Cleaner


Star Brite EZ-ON EZ-OFF Hull Cleaner
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The Star Brite EZ-ON EZ-OFF is the best hull cleaner for heavy-duty stains and deposits.

This is a hydrochloric acid-based cleaner that can almost remove any sort of marine deposits, waterline stains, zebra mussels, and thick crustings. It will also kill grass at the bottom of the boat. 

The manufacturer claims that the product has been made from a buffering process, so the acid is safer. Though it’s true to some extent, if you are spraying, use a respirator. And additionally, use full-length rubber gloves.

It’s available in 128 oz and 32 oz versions. Go for the large one to save more.

We recommend using a soft bristle brush to clean. It will help keep the paint on.



  • Helps to remove tough deposits on hull and boat bottom
  • Kills grass
  • Cheaper than other similar strong acids


  • Requires more precaution than other cleansers


Final verdict

This is a perfect cleaning product for heavy stained fiberglass. But we are still not sure if it would be suitable on aluminum surfaces. If you want to see your boat shining in a few minutes, this is the cleanser to buy. It’s every professional boat detailer’s dream!

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3. MaryKate On and OFF Hull Cleaner


MaryKate On and OFF Hull Cleaner
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If you have a boat that has been lying around in saltwater for years, the Marykate On and OFF is the best cleaning solution for you.

One bottle of this cleanser is enough for an 18 ft boat and probably more.

It will remove all types of stains, yellowing, boat decals, and algae growth.

This cleaning solution has a combination of Hydrochloric acid, phosphoric acid, and oxalic acid. It works perfectly for boat hulls and bottoms. And the best part is it will not harm your gel coat. However, don’t let it sit for too long, and it can sip through.

You need extra precautions when using it like with any other acid-based cleaners.  Use a face mask or respirator, full-length gloves, and natural bristle brush. It will dissolve a sponge applicator, so avoid that.

Overall, it takes just a few minutes to get rid of heavy stains.



  • Combination of several acids that makes the product highly effective
  • Takes very less time to clean
  • Removes almost all stains


  • Requires extra precautions for safety

Final verdict

The Marykate On and OFF works pretty similarly to the Star Brite On and OFF. The price might be the deciding factor here. But a little of this solution is enough to cover large sections of your boat. 

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4. Simple Green All-Purpose Boat Hull cleaner


Simple Green All-Purpose Boat Hull cleaner
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The simple Green is the best multi-purpose boat cleaner we have for you!

As a multi-cleaner, you can’t expect it to remove all heavy stains from the boat hull and bottom. This is the cleanser you should buy to clean your both regularly.

It will remove grease and oil from any surface of your boat. So, basically, you can use it on fiberglass, aluminum, vinyl, boat floor, carpet, and even the seats.

It’s biodegradable and non-toxic. So, you will need no extra precautions and can clean your boat safely in the waters.



  • Non-toxic and biodegradable
  • Safe on skin and marine environment
  • Can be used on all sorts of boat surfaces


  • Not a heavy stain remover

Final verdict

If you want to remove heavy stains and age-old deposits, go for the acid-based cleansers we reviewed earlier. This is an easy to use cleanser that can serve you in multiple ways. Nice to have as an addition for normal cleanups. For effective cost saving, go for the full gallon. 

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5. Booyah Boat Cleaner Duo


Booyah Boat Cleaner Duo
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The Booyah Boat cleaner comes with two boat cleaner- one is non-acidic for cleaning the hull and the other is for general-purpose boat cleaning.

The non-acidic cleaner is an effective alternative to the other acidic cleaners we reviewed earlier. It will remove yellow and brown stains but not so great for removing hard water stains.

The best thing is it will not get rid off the wax on your boat.

So, you need to understand the condition of your boat before buying this product.

It’s really safe on your skin and marine environment.

The boat wash is perfect for cleaning other surfaces of the boat like the floor, seats, and vinyl surfaces.



  • Safe for aquatic life and marine environment
  • Removes light stains and dirt
  • Will not harm the paint and wax on hull bottoms


  • Not a heavy-duty cleaner for age-old dirt


Final verdict

This is a hull cleaner for those who hate handling acidic cleaners and still want an effective cleaning job. Don’t use it for heavy deposits on boats. The addition of the general boat wash is also worth the money. 

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6. MaryKate On and Off Gel Hull Cleaner


MaryKate On and Off Gel Hull Cleaner
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The MaryKate On and Off gel is a decent alternative to the original MaryKate On and Off liquid, we reviewed here. It’s far safer and easy to use compared to the liquid version.

But as a matter of fact, you still need to wear a mask to avoid the smell.

It will clean all sorts of green and yellow stains. It will also get rid of tanning staining. But this is not as powerful as the liquid.

You can use a sponge to clean off the residue after applying.

Though there’s no risk of getting burned as this is a gel medium, you might still want to use protective gloves.



  • Gel medium prevents the risk of spillage and burning
  • Will remove moderate tough stains and discoloration


  • Might not work on heavy deposit stains

Final verdict

The results of the MaryKate On and Off Gel are fast and quite satisfactory. In most cases, this will work like magic. However, having an additional acid-based liquid hull cleaner is recommended.

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7. Star Brite Instant Hull Cleaner Gel Spray


Star Brite Instant Hull Cleaner Gel Spray
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The Star Brite Gel Spray is surprisingly one of the best fiberglass boat hull cleaners.

What we loved is that the spray gel is very easy to apply. No need for goggles, masks, and gloves. Just apply, wait for a few seconds, and rinse off. Most heavy hull stains will go off using this cleanser. And the best part is no scrubbing is needed either. 

The gel is thick enough to stick to vertical surfaces. So, your workload will decrease when cleaning the boat bottom.

It will not run the boat paint, but it can eat away the wax. So, use it for moderate to heavy stained hulls.

One bottle of this cleaning solution will be enough for a 20ft boat.



  • Suitable for moderate to heavy stains
  • Clings onto vertical surfaces
  • No scrubbing required
  • Safe to use
  • Easy to apply


  • Didn’t find any negative sides to mention

Final verdict

If you really want to avoid acid-based liquid hull cleaners, this gel spray should work just fine. Overall, a handy product to have on hand.

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How to clean a boat hull – Full Step-by-Step Guide

We will discuss both basic cleaning and extensive cleaning step by step.

The basic cleaning procedure is for boats with less grease and stain. And then extensive cleaning is for boats that have not been cleaned in months and have been heavily stained.

Let’s start first with basic cleaning.


Basic Hull cleaning – Step-by-step

Step 1 – Use a hose and rinse of as much dirt and algae build-up as possible. 

Step 2 – Dilute a mild hull cleaner in water.

Step 3 – If you’re cleaning your boat in the waters, use a dinghy to get close to the dirty sections of the hull.  For cleaning on land, skip this step.

Step 4 – Scrub the hull down to the waterline.

Step 5 – Using a soft sponge apply the cleaning solution to every section of the hull. Remember to wring out the sponge and use a circular motion when applying.

Step 6 – Wait for a few minutes for the solution to react. Then wipe off with a sponge soaked in clean water.


Extensive Hull cleaning – Step-by-step

Step 1 – Rinse the hull with water to remove loose dirt and algae.

Step 2 – Use a very strong acidic hull cleaner and follow the dilution requirements.

Step 3 – Use a spray and apply the solution to the hull.

Step 4 – Let the solution sit for a few minutes. In most cases, you will see most of the dirt already gone. If not, wait for up to 15 minutes.

Step 5 – Use bristle brush to get rid of the grime

Step 6 – Use a clean wet sponge to wipe off the remaining. If you are on land, you can rinse it off. 

Top 6 boat and hull cleaning tips

#Tip 1 – You should regularly clean your boat and the hull. This will minimize the need to use toxic hull cleaners. So, you save- time + money + environmental pollution.

#Tip 2 – Use toxic hull cleaners in small portions and wipe them out with a towel instead of washing them off. This will minimize environmental pollution.

#Tip 3 – Using a protective boat wax will help to resist stain and grease build-up. However, in that case, you will need to use mild cleaning products.

#Tip 4 – Read the labels after you buy a cleaning product. Follow the dilution requirements properly.

#Tip 5 – Use biodegradable hull cleaners as much as you can!

#Tip 6 – It’s best to wash your boat taking it away from the water. Best is to dispose of the residue near suitable areas.

Here’s a video of a boat that has been cleaned from trash to gold. This should give you some inspiration-


Best boat hull cleaner buying guide

1. Acid cleaners vs. acid-free cleaners

The first thing to consider when buying a hull cleaner is to choose between acidic and non-acidic cleaners.

This will depend on the amount of grease you have on the hull. If the boat has been sitting around for ages, you will need something acidic. Most preferably, a cleaner that has muriatic acid. And other acids will also do the job.

But using an acid-based hull cleaner will need you to take some extra precautions. It can cause skin and eye irritation and can even burn your clothing.

For less stubborn stain, a non-acidic environmentally friendly hull cleaner will just work fine. These are usually biodegradable.


2. Quantity to purchase

Cleaning a hull may require quite some amount of cleaning agent. So, you should buy in gallons, rather than pints.

This will save a lot of money in the long term.


3. Type of stains on the hull

Depending on the type of stain, your decision to purchase a hull cleaner will vary. Some stains will leave a brown color, others will be subject to algae and mold growth.

Look for the hull cleaner reviews and product description to find out what sort of stains a particular cleaner can get rid of. 


4. Cleaning power

By cleaning power, we mean- how fast the cleaning agent work and how deep it can clean.

So, this should be an important criterion to buy a hull cleaning agent.

Keep in mind, the more powerful the cleaning agent is, the higher the precautions you need to take.


5. Choosing between different types of hull cleaners

In general, you will find 4 types of hull cleaners:


  • Liquid hull cleaners
  • Gel-based hull cleaners
  • Spray hull cleaners
  • Powder hull cleaners


We reviewed liquid, gel-based, and spray hull cleaners. We left out the powder versions because we are still unclear about their effectiveness. Once we test it out, we will provide an update to this review.

In terms of safety, the gel cleaners are the best hull cleaners for boats. The performance is also quite satisfying.

If you can take precautions, then the liquid cleaners will outperform all. But these can be harsh for the environment. 


6. Price range

You will need to spend anything between $7 to $20 and up for a high-quality hull cleaner. Liquid hull cleaners will cost you more. And the cheapest option is a gel-based cleaner.

If you are not using professional hull cleaning services, the price of hull cleaning agents will not matter that much. However, it can add up to the cost of maintenance considerably if you opt for a professional service. 

Boat hull cleaner FAQ

1. What kind of stains or dirt forms on boat hulls?

These are the following types of dirt that form on a hull:


  • Brown or gray stain
  • Speckled black dots
  • Greasy scum
  • Algae and mold growth
  • Metallic salts
  • Mustache Scum lines


2. What are some of the essential acids needed for cleaning boat hulls?

These are some of the common acids found in hull cleaning products:


  • Oxalic acid
  • Phosphoric acid
  • Sulfuric acid
  • Hydrochloric acid
  • Hydrogen chloride
  • Muriatic acid


3. Can I use household cleaners instead of dedicated hull cleaners?

Household cleaners can work. But they will be able to remove only some of the scum and dirt. The brown stains commonly found on hull surfaces will not get off using household cleaners. 


4. How to clean a fiberglass boat?

Without rushing into specialized hull cleaners, first, start off with a household detergent and dilute it in water. Use a sponge for the task.

Don’t use bleach. However, for mildew, you can add bleach to your cleaning solution.

If the stains are too tough, go for a fiberglass hull cleaner.

Here’s a demonstration on cleaning fiberglass a hull-


5. Can I use DIY boat cleaning techniques?

DIY methods may or may not work. So, you can experiment. Some of the components commonly used in DIY boat cleaning are:


  • Dishwashing liquid
  • Vinegar
  • Baking soda
  • Acetone or paint thinners
  • Rust remover
  • Hydrogen peroxide
  • Detergent
  • Wax


Here’s a post on cleaning Fiberglass components with DIY methods.


6. What do you wipe down a boat with?

Usually, anything that contains microfiber will get your job done. So, a towel or sponge should be okay to use.


7. Do I need to hire a professional for boat cleaning?

For cleaning the hull, professional service is not mandatory.

However, if you need to clean the bottom of your boat and cannot get the boat out of the water, a professional cleaning service will become necessary.

You might need to pay between $.2.5-$3.5 per foot. 


8. How often should I clean my boat hull?

According to Fast Bottoms Hull Diving, the frequency of cleaning your boat and the hull should be after every two months. Cleaning every once a week will be expensive. And if you leave it without cleaning for more than two months, the antifouling on the boat might come off while cleaning. 


9. How often should I Antifoul my boat?

It’s best to book for an antifouling service after every 9-15 months. But it will depend on the frequency of boat use, quality of the waters, and the environment. 


10. Can I use a car wash cleaner on my boat?

Yes, you can use car wash products on boats. But you need to be careful about the harshness of these products. It should be friendly on the wax coating of the hull.


11. Are biodegradable hull cleaners really biodegradable?

We talked with many marine and boat specialists. On paper, yes, these hull cleaners are biodegradable. However, these cleaners will still take a longer time to degrade. So, it’s best to clean the boat on land where the residue can flow through the sewage.


12. My boat remains in colder water. Should I clean it?

It’s true that boats in colder waters require less maintenance and are not too much susceptible to marine growth. But still, routine cleaning is necessary.

Sources & References

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