Best Cleaner For Fiberglass Boat

The hull is the most exterior part of your boat, and it’s, therefore, more exposed to wear and tear than other parts. That’s why it needs regular maintenance to keep it in top shape and maintain its appearance.

Fiberglass is the most popular material used to build modern boats. It’s strong, lightweight, good for speed, and affordable. It also has a shiny appearance, which looks good on any boat.

Cleaning your fiberglass boat keeps it in its best appearance and prevents wear and tear. However, since fiberglass has a delicate surface, you need to be careful about the kind of cleaner that you use on it.

That’s why you cannot just go and pick any cleaner from the store. You need to look at things such as the composition of the cleaner, how it cleans the boat, toxicity, versatility, and many other factors.

In today’s review, we’ll look at 9 cleaners for fiberglass boats that can do a good job in various situations. By the end of this list, you should be able to find a cleaner for a fiberglass boat that suits your vessel.

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Star Brite

Boat Bling


The 9 Best Cleaners for Fiberglass Boat Reviews

1.  Star Brite Instant Hull Cleaner

STAR BRITE Instant Hull Cleaner - Gel Spray Formula 32 oz

The Star Brite Instant Hull Cleaner is a quick-acting cleaner that removes fish blood, rust, and waterline stains. It also rids of stains caused by light marine deposits and leaves.

What I like most about the Star Brite Instant Hull Cleaner is that it removes tough stains in a single application. And, this is without any scrubbing required.

To use, shake well and apply on the fiberglass surface of your boat using a sponge or sprayer. Wear rubber gloves when using to avoid skin irritation. Leave it to rest for 2 minutes, then rinse with clean water.

If your boat is severely stained and everything doesn’t come off with the first try, a second application can get the work done.

This cleaner is marine-grade with a user-friendly oxalic formula. It does not contain any harmful acids. Besides being a safe cleaner for fiberglass hulls, it can also be used on metal and painted surfaces.

For the best results after cleaning, use this cleaner when the temperature is above 50°F.


  • It removes dirt instantly with a single application.
  • Gets rid of all tough stains, including rust, waterline, and fish blood.
  • Can be used on multiple surfaces, including fiberglass, metal, and painted.
  • Doesn’t contain harmful acids that could corrode the fiberglass.


  • Can only work best when used in temperatures of 50°F and above.

2.  Boat Bling Quickie Sauce Fast Wax

Boat Bling Quickie Sauce Premium High-Gloss Fast Wax, 32 oz.

Get rid of stubborn grime and add shine to your fiberglass hull with this boat wax. It cleans off the scum line, hard water residue, and exhaust residue, all without stripping off the wax.

It contains wax sealants that leave your boat looking glossier with extra protection against the sun’s ultraviolet rays. Since the gel-coat and painted surfaces receive extra protection, cleaning after a long trip on the water will be much easier.

The premium Montana wax formula used is of high quality and lasts for long in the marine environment. On application, this wax will provide protection to your hull for about 3-4 months.

This product can be used safely on fiberglass, painted, chrome, plastic, and glass surfaces. It’s easy to use, only requiring to be sprayed on the surface, rubbed in, then wiped off.

It’s also safe to use on decals and vinyl moldings. Due to its versatility, it’s a great value for money as you’ll be able to use it on multiple surfaces in the boat besides those made of fiberglass.


  • Safe for use on multiple surfaces including fiberglass, painted, metal, and plastic.
  • Provides extra protection from the sun’s ultraviolet rays.
  • It’s gentle on the gel coat and adds wax sealants to the surface.


  • It’s a bit pricey.

3.  Collinite 920 Boat Cleaner and 925 Boat Wax Combo

Collinite 920 Fiberglass Boat Cleaner & 925 Fiberglass Boat Wax Combo Pack

This cleaner and wax combination allows you to rid of all the stains and dirt on your boat and to leave it shining and with added protection.

The cleaner removes light oxidation, discoloration, film, and tough stains that could have formed on your fiberglass boat. This restores the boat’s original color and shine. It also prepares the boat for wax application.

The 925 wax leaves your fiberglass boat glistening and provides lasting protection to the finish. It protects against harmful UV rays, corrosion, chalking, marine growth, and stains.

This keeps your boat looking great for much longer after cleaning. Ensure to use the 920 cleaner well before applying the wax so that it can last longer.


  • The cleaner removes tough stains from fiberglass without damaging the gel coat.
  • Restores original color and gloss by fixing discoloration.
  • The cleaner paves the way for better wax application and enhances its durability.
  • 925 wax provides added protection against stains, corrosion, and UV rays.


  • When you go for this product listing, you have to buy both the cleaner and wax even if you only need one.

4.  Meguiar’s M67 One Step Compound

Meguiar's M6732 Marine/RV One Step Compound, 32 oz

Meguiar’s M67 One Step Compound removes dirt and stains while restoring your boat’s gloss in one go.

This is a product that you should use when you want to remove under-the-surface defects that don’t come off easily with a basic wash. Before using it, clean your boat and let it dry completely.

Only apply this compound when the boat is dry and cool. This is a fast-acting formula that should be used a section at a time. After dispensing it on the boat surface, wipe it off immediately with a clean cotton towel.

Don’t let the compound to dry on the surface of the boat, and this is why you should work one section at a time. This product can be applied by either hand or machine.

This is a great product if you need to remove heavy oxidation, light to medium scratches, and stubborn water spots. It also restores color, shine, and luster.

It cleans the gel-coat thoroughly without stripping it away. Since it compounds and polishes the fiberglass surface with a single application, it’s a faster and more convenient way to restore neglected surfaces on your boat.


  • Compounds and polishes fiberglass surface in one go.
  • Removes heavy oxidation and stubborn stains that don’t come off with regular boat wash.
  • It has a quick-acting formula.


  • Requires a lot of care and attention when using to avoid damaging the boat’s gel coat or fiberglass surface.
  • May cause irritation to the skin and eyes.

5.  Meguiar’s M4364 Boat Wash

MEGUIAR'S M4364 Marine/RV Boat Wash, 64 Fluid Ounces, Beige, 3.2 x 10.2 x 5.4 inches

This boat wash from Meguiar’s stands out from the rest thanks to its long-lasting sudsing power. It’s also gentle on fiberglass while being tough on stains and dirt.

It removes waterline scum, fish blood stains, grime, dirt, and marine deposits from your boat’s surface without stripping the wax protection.

It’s a better option compared to dishwashing detergents, which can strip your boat’s polish, wax, and lead to oxidation.

This boat wash also contains rich conditioners that brighten the finish, leaving your boat looking as good as new. It also has a refreshing scent, which will leave your boat smelling fresh with no strong odors.

To get the best results, use this product on a cool surface, and work in a shaded area. 1oz of the wash should be diluted with 1 gallon of water. Apply it on the boat using a wash pad then rinse with a flow of water.

Dry it with a clean, 100% cotton towel. Avoid using materials that are abrasive on the fiberglass surface. This formula is pH neutral and poses no harm to your boat or the environment.


  • It’s a non-detergent formula that doesn’t strip the wax or polish.
  • Has great sudsing power for gentle cleaning.
  • It’s pH neutral and poses no toxicity risk to the environment.
  • Contains conditioners that leave your boat looking brighter.


  • Requires a scrub pad to use.

6.  3M Marine Cleaner and Wax, 09009

3M Marine Cleaner and Wax, 09009, 16.9 fl oz

If you’re looking to reveal the color and shine of your fiberglass hull, this cleaner and wax formula can be a great fit. It removes filmy residues from the water, exhaust stains, rust deposits, and dock skid marks.

It also strips away light oxidation, hence revealing the original color and shine of the fiberglass. This product cleans, polishes, and provides protection to the gel-coat.

It compounds and waxes the surface in one application, leaving behind a brilliant high gloss and protective finish. This removes damage done by ultraviolet rays and also prevents future damage.


  • It cleans the fiberglass efficiently by removing water residues, skid marks, exhaust stains, and rust deposits.
  • Removes light oxidation to reveal the color and original shine of your boat.
  • Contains a unique blend of waxes that restore the high gloss of the fiberglass and provide protection against oxidation and sun damage.


  • Only removes light to medium oxidation, so it might not be a good fit if your boat is heavily oxidized.

7.  MaryKate MK2032 On & Off Hull & Bottom Cleaner

MaryKate MK2032 Marykate On & Off Hull & Bottom, 32 fl oz

This hull and bottom cleaner from MaryKate is a good option for people looking to get rid of tough water spots, algae, rust, and exhaust stains.

It’s a fast-acting formula that removes dirt and stains instantly, so you’ll not spend a lot of time waiting around for it to dissolve the grime off your fiberglass.

While it’s a good cleaner that’ll leave your boat shining without stripping the wax and gel-coat, it’s strong enough to cause skin burns, eye damage, and respiratory tract irritation.

The one downside of this cleaner is that it can only be used on fiberglass, unlike others on this list that are versatile and can be used on other types of surfaces.


  • Removes stains and residues on fiberglass surfaces instantly.
  • It’s gentle on the gel-coat.


  • It cannot be used on other surfaces besides fiberglass.
  • Poses a high possibility of respiratory tract irritation, eye damage, and skin burns if not handled cautiously.

8.  Davis Instruments FSR Big Job Bottle

Davis Instruments FSR Big Job Bottle, 2 Litter (792)

If you need to remove stains from the fiberglass or white painted surface of your boat, Davis FSR stain remover could be what you need.

This is a non-abrasive formula that strips away dirt, fish blood and bait stains, and residue on the waterline.

It has an oxalic acid-based formula that gets neutralized in water and is biodegradable and therefore doesn’t cause pollution to the water body.

If your cutting boards have been discolored due to staining or oxidation, this product can bleach them white again.

Besides using this on your fiberglass boat, you can also use it to clean and brighten RVs, fiberglass shower stalls, and swimming pools.


  • It’s a non-abrasive cleaner that gets rid of tough stains while protecting the delicate gel-coat.
  • Can be used on both fiberglass and white painted surfaces.
  • Suitable for use in many settings, including boats, RVs, and swimming pools.


  • Might not work well on super tough stains.

9.  Better Boat Hull Cleaner

Better Boat Hull Cleaner for Fiberglass and Painted Boats Cleaning Marine Stain Remover 32oz

This Better Boat hull cleaner works well on fiberglass and painted surfaces. It dissolves and disintegrates scum on these surfaces and cleans them off, leaving the hull looking new.

To use, apply it, wait for about 2 minutes, then rinse with clean water. With such a simple application, it’ll get rid of buildup from the exhaust, rust, and waterline stains.

It’s a great product to use to get rid of both new and old stains on fiberglass, metal, and aluminum surfaces. It also removes discoloration and allows white surfaces to regain their shine.


  • Removes dirt and stains without the need for scrubbing.
  • Brightens white surfaces by removing discoloration.
  • Can be used on fiberglass, aluminum, and metal surfaces.
  • Removes tough stains with a single application.


  • Leaves behind a strong smell that can be unpleasant to some.

Things to Consider When Buying a Cleaner for Fiberglass Boat

In order to choose the best cleaner for your fiberglass boat, it’s important to know what to look for. Since there are so many cleaners in the market claiming to do a great job, here are few factors you should consider to ensure that you end up with the best:


While the ability to remove dirt and stains is a desirable quality in a boat cleaner, it’s important to look at what ingredients are used to enable this cleansing action.

First of all, they should be gentle on the fiberglass surface, which can become damaged if exposed to strong corrosive chemicals. The formula used should also be biodegradable to ensure that it doesn’t cause water pollution if it ends up in the water body.

Quick Action

If you don’t want to sit around waiting for a cleaner to dissolve stains so that you can rinse it off, you should look for a fast-acting formula. Such a cleaner will be able to remove stains just a few minutes after application without stripping the wax or gel-coat.

A fast-acting product is especially convenient when you’re cleaning the hull, which is a large area. The faster that it works, the sooner you’ll finish the cleaning.

Mode of Usage

Some cleaners can be sprayed on the fiberglass surface then wiped off to remove dirt and stains. Others need to be diluted with water and applied on the boat using a wash pad.

The mode of usage of a cleaner determines how much time and effort you’ll use to clean your boat. Go for the method that you find to be most convenient for you.


A good fiberglass boat cleaner should also be suitable for use on other surfaces. From my list, you can see that some cleaners can also be used on metal, plastic, and painted surfaces. This’ll allow you to buy just one product for multiple purposes, saving you money.


How do fiberglass boat cleaners work?

Fiberglass boat cleaners work by penetrating stains and dirt on the surface, then dissolving them away. In this way, they clean the surface and restore shine while providing protection against pollution and oxidation.

How often should you clean your boat?

How often you clean your boat should depend on how frequently you use it. If you’re on the water a lot, then you’ll need to wash it regularly to keep it from wearing out and to prolong its lifespan.

What are the different types of fiberglass boat cleaners?

Most fiberglass boat cleaners can be found in two types, in liquid or gel form. They both work to remove dirt and stains, but gel cleaners are easier to use as they’re not messy.


Cleaning your fiberglass boat is an important step in ensuring that it lasts for as long as possible. It also helps preserve its shiny and glossy appearance and prevents discoloration.

When shipping for a cleaner for a fiberglass boat, make sure to consider the factors that I’ve mentioned here. That way, you’ll end up with an effective cleaner that’s easy on your delicate fiberglass surface but tough on stains.

Also, go for a cleaner that provides extra protective benefits that ensure that your boat remains in its best condition for long.

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