Barnacles and other marine growth can slow down your vessel, increase fuel consumption, and damage the hull over time. That’s why we have compilled the best boat bottom paints to help you pick the right ones.
Boat bottom paint, also known as antifouling paint, creates a protective barrier that prevents these organisms from attaching to your boat’s underwater surface.
There are several types of bottom paints available, including hard, ablative, and hybrid formulations.
Hard paints create a tough coating that resists wear but may build up over time and require sanding.
Ablative paints slowly wear away, continuously exposing fresh biocide to deter marine growth.
Hybrid paints combine features of both types for versatile protection.
Environmental regulations have led to changes in paint formulas, with copper-based options replacing more toxic compounds.
We tested the most popular boat bottom paints to find which ones best protect against barnacles while remaining environmentally responsible.
Best Boat Bottom Paints to Prevent Barnacles
We’ve tested and reviewed the top boat bottom paints that effectively prevent barnacle growth and marine buildup. These high-performance coatings will help keep your hull clean while extending the time between necessary maintenance.
Our selections balance longevity, application ease, and environmental considerations to give you the best options for your vessel.
1. TotalBoat Underdog Bottom Paint
TotalBoat Underdog offers effective single-season barnacle protection at an affordable price, making it ideal for boat owners who want reliable performance without breaking the bank.
Pros
- Economical price compared to other antifouling paints
- Ablative coating prevents paint buildup for easier future applications
- Includes helpful application accessories with purchase
Cons
- Works best for single-season use only
- Some packages reported arriving damaged during shipping
- May require more frequent application than premium brands
This copper-based paint effectively prevents barnacles and other marine growth from sticking to your boat’s hull.
The ablative formula gradually wears away in the water, continually exposing fresh biocide. This feature means less buildup over time, which saves work during future applications.
We found Underdog particularly suitable for fiberglass, wood, and steel hulls.
It can be applied with a brush, roller, or spray equipment for flexibility. The coverage rate of 500 square feet per gallon provides good value for most recreational boats.
Many boaters appreciate the extras included with their purchase – application tools like rollers, trays, and protective gear.
The paint’s durability against trailering and beaching makes it practical for active boaters.
Available in black, blue, and red, Underdog competes well with more expensive brands while delivering reliable protection for boats used regularly in saltwater environments.
2. TotalBoat Spartan Antifouling Paint
This high-copper bottom paint offers multi-season protection against barnacles and marine growth, making it a solid choice for boat owners facing tough fouling conditions.
Pros
- High copper content (38%) provides strong protection in all water types
- Can be hauled and relaunched without repainting (just light scuffing)
- Works on multiple surfaces including fiberglass, wood, and steel
Cons
- Some users report mixed results with barnacle prevention
- May require multiple coats for best protection
- Higher price point compared to basic bottom paints
TotalBoat Spartan delivers reliable performance through its ablative formula. The paint slowly wears away over time, continuously exposing fresh biocide to prevent marine growth.
This self-polishing action reduces buildup and makes future paint jobs easier by eliminating heavy sanding.
One standout feature is its versatility across different environments.
Whether your boat stays in fresh, salt, or brackish water, the 38% copper oxide content works to repel unwanted hitchhikers.
The smooth, abrasion-resistant finish also helps improve your boat’s speed and fuel efficiency.
The application is straightforward, with options for brushing, rolling, or spraying.
A gallon covers about 500 square feet, which is enough for most small to medium boats.
We appreciate that it comes in several color options, including blue, black, green, and red.
For boaters who need to haul out temporarily, the ability to relaunch without repainting saves both time and money.
3. Rust-Oleum Marine Bottom Paint
This copper-based antifouling paint offers excellent protection against barnacles and marine growth for boats in both fresh and saltwater environments.
Pros
- Effective protection against barnacles and algae
- Works on multiple surfaces (fiberglass, wood, steel)
- Quick drying with recoat time of just 4 hours
Cons
- Not suitable for aluminum boats
- Strong odor during application
- Requires launching within 60 days for best results
Rust-Oleum’s boat bottom paint creates a hard, smooth barrier that slowly releases copper to prevent unwanted marine growth.
The formula works best in mild to moderate fouling conditions, making it ideal for boats that don’t face extreme marine environments.
One quart covers up to 110 square feet, which is enough for many small to medium-sized vessels.
Application is straightforward but requires proper preparation.
The paint dries quickly, allowing for a second coat after just 4 hours. Boats can be launched only 16 hours after the final application.
We appreciate the flat black finish that provides a clean, professional look while effectively doing its job below the waterline.
For trailer boats that spend time in and out of water, this paint offers a good balance of durability and protection.
The hard finish resists damage from trailering while still providing antifouling benefits when in water.
Remember that this product isn’t suitable for aluminum boats or for use in certain regulated areas like Catalina Island.
4. TotalBoat JD Select Bottom Paint
We recommend TotalBoat JD Select for boaters seeking an effective, eco-friendly ablative paint that prevents marine growth while being easier to apply than most competitors.
Pros
- Water-based formula with low VOCs and easy soap-water cleanup
- Works in both salt and fresh water environments
- Self-polishing coating reduces build-up and future sanding needs
Cons
- Some users report needing multiple coats for full coverage
- More expensive than basic bottom paints
- May not last as long in high-fouling areas
TotalBoat JD Select offers seasonal protection against barnacles, slime, and weeds that can slow down your vessel and increase fuel costs.
The hybrid ablative formula gradually wears away as your boat moves through water, which helps prevent excessive paint buildup over multiple seasons. This means less sanding work when it’s time to reapply.
Application is straightforward with brush, roller, or spray equipment.
You can use it on fiberglass, wood, steel, and iron hulls. The paint can go over most existing bottom paints in good condition.
With coverage of about 500 square feet per gallon, a little goes a long way for most recreational boats.
We particularly like that this USA-made product considers environmental concerns.
The water-based formula has no toxic fumes and meets restrictions in environmentally sensitive marinas.
Available in black, blue, green, and red, it provides both protection and a clean look below the waterline. The self-polishing nature also allows for burnishing to improve speed and fuel efficiency.
5. Interlux Fiberglass Bottomkote NT Blue
This dual-resin antifouling paint offers the best of both hard and ablative formulas, making it a solid choice for boat owners looking for season-long protection.
Pros
- Combines benefits of hard durability with slow-polishing features
- Can be applied and launched same day thanks to fast-drying formula
- Works in fresh, salt, and brackish waters
Cons
- Not suitable for aluminum hulls
- May wear off under high friction (like straps)
- Requires proper ventilation during application
The Interlux Bottomkote NT uses smart technology that prevents barnacles while avoiding excessive paint buildup over time.
Its slow-polishing action continuously smooths and renews the surface with use. This means your boat maintains a clean, efficient hull without needing frequent repainting.
Coverage is impressive, with one gallon treating approximately 500 square feet of hull surface.
We found the blue color stays vibrant throughout the season and provides a glossy finish that looks professional. The paint adheres well to fiberglass, wood, and properly primed metal surfaces.
Boaters appreciate that this formula allows same-day launching after application.
The dual-resin approach creates a surface that gets smoother with use, potentially improving fuel efficiency.
Buying Guide
When choosing boat bottom paint to prevent barnacles, several factors come into play. We’ll help you understand what to look for to make the best decision for your vessel.
Types of Paint
Different paints work in various conditions:
- Hard Paint: Durable, can be scrubbed, good for speed
- Ablative Paint: Wears away slowly, releases biocide continuously
- Hybrid Paint: Combines features of both hard and ablative paints
- Copper-Free Paint: Environmentally friendly option
Water Conditions
Your boating environment matters a lot when selecting paint.
Fresh water and salt water require different paint formulations. Boats in warmer waters typically need stronger anti-fouling protection since marine growth is more aggressive in these conditions.
Boat Usage
How you use your boat should influence your paint choice.
Boats that sit in marinas most of the time need stronger protection than those used regularly. Racing boats benefit from hard, smooth paints that reduce drag.
Application Method
Consider how the paint will be applied:
| Application Method | Pros | Cons |
|---|---|---|
| Spray | Even coverage, faster | Requires special equipment |
| Roller | Easy DIY method | May show stroke marks |
| Brush | Good for detailed areas | Time-consuming |
Environmental Concerns
Many regions have restrictions on certain biocides. You should check local regulations before making your final decision.
