For Australian boat owners who keep their vessel in the water, marine growth and ongoing hull maintenance can be an unavoidable part of boating. Antifoul has traditionally been used to manage marine growth on submerged hulls — but what if there was another, easier way?
SeaPen offers an alternative to antifoul by keeping your boat clean, dry and free from marine growth between uses.
Instead of physically lifting your boat out of the water, SeaPen creates an isolated enclosure around your vessel. Automated pumps remove the water from the enclosure, allowing your boat to remain dry at water level between uses.
So, how does SeaPen compare with antifoul, and why are Australian boat owners choosing water-level dry docking?
What is antifoul?
Antifoul is a coating applied to the underwater surfaces of a boat to help reduce marine growth attaching to the hull.
Many conventional antifouling coatings work by gradually releasing biocides—commonly copper-based compounds—designed to discourage marine organisms from attaching. However, antifoul does not prevent marine growth indefinitely. Barnacles, algae and weed may still begin appearing within months, depending on the conditions and how frequently the boat is used.
Scientific research has also found that copper, zinc and antifouling paint particles can enter surrounding waters and may affect non-target marine organisms. Australia’s State of the Environment report identifies copper pollution from antifouling coatings as an environmental pressure associated with recreational boating.
For boats permanently stored in the water, antifouling forms part of an ongoing maintenance cycle. The hull still requires cleaning, and the antifoul must be reapplied over time to continue performing its intended purpose.
SeaPen approaches marine growth differently.
Instead of using a biocidal coating to manage marine growth while the hull remains submerged, SeaPen keeps the hull dry between uses. This removes the wet conditions marine growth needs to establish and eliminates the need for antifoul while the boat is correctly stored in the system.
For boat owners looking for a cleaner, lower-maintenance alternative, SeaPen avoids ongoing antifoul application while helping keep the hull clean, dry and ready to use.
What is SeaPen?
SeaPen is an Australian-made water-level dry-docking system designed to keep your boat hull clean, dry and free from marine growth without lifting your vessel out of the water.
Your boat enters and exits the SeaPen naturally at water level. Once your boat is inside, the rear gate closes and the automatic pumping system removes water from around the hull.
A patented woven rope mat cradles the vessel at the waterline and creates airflow beneath the hull, helping keep it dry and ventilated between uses.
The result? Your boat stays conveniently in its berth, but the hull doesn’t remain sitting in the surrounding water, so there is no opportunity for marine growth.
SeaPen vs antifoul: what’s the difference?
The biggest difference between SeaPen and antifoul is how they deal with marine growth.
Antifoul is applied to a hull that remains submerged to help manage marine growth.
SeaPen takes the hull out of that environment by keeping it dry between uses.
| Antifoul | SeaPen |
| Applied to underwater surfaces | Water-level dry-docking system |
| Hull remains submerged while stored | Hull remains dry between uses |
| Toxic chemicals released to kill marine growth | Non-toxic, environmentally friendly. Designed to prevent marine growth while dry-docked |
| Requires ongoing yearly application = money + time wasted | No antifoul required while correctly stored |
| Part of wet-storage hull maintenance | Designed to reduce ongoing hull maintenance |
| Ongoing cost | Investment |
| No asset at the end, throwing money away | Gain an asset, that can be sold with the boat |
Rather than continually managing marine growth on a wet hull, SeaPen addresses the problem at its source by keeping the hull dry, and at the end of your boats life and you want to upgrade, the SeaPen can be sold as an asset along with the boat.
Growth on a boat that was antifouled and kept in the water for only 6 months. Changed their mind and now going to be kept in a SeaPen.
Can you keep a boat hull clean without lifting the boat?
Yes. SeaPen keeps your boat hull dry without physically lifting the vessel above the water.
This is what makes SeaPen different from a traditional boat lift.
Your boat simply enters the SeaPen at water level. Once inside, the rear gate closes and the automatic bilge pump removes water from around the hull.
The woven rope mat creates an air gap between the hull and the SeaPen’s inner skin, allowing ventilation around the hull and running gear.
Your boat remains floating naturally at water level while its hull stays dry and protected from marine growth between uses.
It’s water-level dry docking — no boat lift and no antifoul required.
Do you need antifoul with a SeaPen?
No. Antifoul is not required to keep your boat free from marine growth while it is correctly dry-docked in a SeaPen.
Boats stored in the water are continually exposed to barnacles, algae and weed, which can build up over time – even on antifouled hulls. This growth creates drag and requires ongoing cleaning, maintenance and regular antifoul reapplication.
A SeaPen keeps your boat dry at water level between uses, removing the wet conditions marine growth needs to establish on the hull. This allows owners to avoid the ongoing cost and inconvenience of antifouling while keeping their boat cleaner and ready to use.
For fibreglass boats, we recommend applying a suitable barrier coat before using a SeaPen, or any dry-docking device for that matter. A barrier coat is not antifoul; it is a non-toxic protective coating designed to seal and waterproof the hull. This only needs to be reapplied every 5 or so years. Speak to your boat manufacturer about who they most recommend for this.
How does SeaPen prevent marine growth?
SeaPen is designed to prevent marine growth by keeping the surfaces of your boat that would normally be underwater dry between uses.
The process is simple:
- Open the rear gate using the remote.
- Drive your boat into the SeaPen at water level.
- Close the rear gate.
- The automatic bilge pump removes water from around the hull.
- The rope mat provides airflow beneath the hull to keep it dry and ventilated.
- When you’re ready to go boating, open the gate and drive out.
The automatic pumping system also checks for water every two hours and removes it when detected.
Instead of leaving the hull continuously exposed to the surrounding water, SeaPen creates a dry environment around your vessel while it is stored.
What are the benefits of SeaPen compared with antifoul?
No antifoul required
Keeping the hull dry removes the need for antifoul to prevent marine growth while your boat is correctly stored in the SeaPen.
Helps prevent marine growth
Preventing marine growth is the primary purpose of SeaPen. By keeping the normally submerged surfaces of your vessel dry, SeaPen helps keep your hull clean between uses.
Less ongoing hull maintenance | Time and Money Saved Every Year
Antifouling isn’t just a monetary cost – it’s time as well. Hauling your boat out, preparing the hull, applying antifoul and waiting for it to cure can take multiple days out of your year, time that could otherwise be spent out on the water.
With a SeaPen, that annual haul-out and antifoul cycle is no longer needed. Owners get those days back, along with the ongoing savings that come from not paying for antifoul products, application labour and slipway fees year after year.
Please note: Removing the need for antifouling doesn’t remove the need for maintenance. Ongoing servicing of both your vessel and your SeaPen should still be budgeted for and carried out as recommended.
Your boat remains at water level
There are no cranes or hoists involved. Your vessel remains naturally floating at water level inside its existing suitable berth. This makes it easier, and safer to access, as well as having no-point loads on your vessel.
Easier access to your boat
SeaPen can provide perimeter access around your vessel, making it easier to access, clean and maintain your boat while it remains in its berth.
Australian-made
SeaPen is proudly designed and manufactured on the Gold Coast for Australian marine conditions. The original concept was developed in 1997, before the first official SeaPen launched in 2004. Since then, we have spent more than 22 years continuously refining and improving the system.
Is SeaPen more environmentally friendly than antifoul?
Avoiding antifoul is one of the environmental benefits behind the SeaPen concept.
DOCKPRO’s commitment to making boating easier, cleaner and more sustainable was recognised with the 2025 BIA Sustainability in the Boating Industry Award.
Based on typical antifouling usage of around 10L per vessel per year, and an average SeaPen lifespan of 10 years, each SeaPen is estimated to prevent more than 100L of antifouling paint from being applied to a single vessel.
For boat owners looking for another way to manage marine growth, keeping the hull dry provides an alternative to repeatedly applying antifoul.
What boats can use a SeaPen?
SeaPen is designed for recreational and light commercial vessels approximately 6 to 20 metres long.
Compatible vessel types include:
- Monohulls
- Catamarans
- Tri-hulls
- Pontoon boats
- Wake and ski boats
- Trailer-sailors
SeaPen can also accommodate a range of drive types, including:
- Outboards
- Stern drives
- Jet drives
- V-drives
Every boat and berth is different, so vessel specifications and installation conditions need to be considered when determining the right SeaPen setup.
Where can a SeaPen be installed?
SeaPen is designed to integrate into suitable existing berths and is compatible with both floating pontoons and fixed jetties.
It is suited to calm-water environments such as marinas, canals and sheltered waterways.
Water depth, current and wave action are important when determining whether a location is suitable for SeaPen.
SeaPen requires a minimum water depth of 50 centimetres plus the vessel’s draft, with local environmental conditions considered as part of the setup.
SeaPen installation and service support near you
SeaPen is an Australian-made water-level dry-docking solution available to boat owners across Australia and New Zealand.
SeaPens are already installed in Sydney, Melbourne, Auckland, Mandurah, the Gold Coast and surrounding areas, helping owners keep their hulls dry while their boats remain conveniently at water level in their berths.
DOCKPRO provides SeaPen installation and ongoing service support in each of these regions, making it easier to have the right system installed and maintained over the long term.
To find out whether SeaPen is suitable for your boat and berth, simply provide your boat make, model and location, and our team can assess your setup.
Does SeaPen prevent osmosis?
No, SeaPen does not prevent osmosis, and no dry-docking system should be considered a substitute for appropriate hull protection.
Osmosis occurs when water passes through a boat’s gelcoat and becomes trapped within the fibreglass laminate. Over time, this can lead to fluid-filled blisters on the hull, known as osmotic blistering. Any time a fibreglass boat is in the water—including while it is being used—the hull is exposed to moisture and the potential for osmosis.
SeaPen’s primary purpose is to prevent marine growth and reduce maintenance on areas of the vessel that would otherwise remain underwater. However, antifoul and hull protection serve different purposes. Antifoul helps manage marine growth, while a suitable barrier coat helps protect the hull from moisture penetration.
SeaPen—and other dry-docking systems—should not be considered a solution for preventing osmosis or osmotic blistering. Boat owners removing antifoul should seek professional advice about applying and maintaining an appropriate barrier coat to protect the underlying hull.
SeaPen vs antifoul: which should Australian boat owners choose?
If your goal is to keep your boat hull clean from marine growth while reducing the ongoing maintenance associated with wet storage, SeaPen offers the best Australian-made alternative to antifoul.
Rather than leaving your hull submerged and using antifoul to manage marine growth, SeaPen keeps the hull dry between uses.
Your boat remains conveniently at water level in its berth. The hull stays clean and dry. There’s no need to physically lift the vessel, and no antifoul is required to prevent marine growth while your boat is correctly stored in the SeaPen.
It’s a different approach to boat storage — designed to make owning and using your boat easier.
Looking for an alternative to antifoul?
If you’re considering moving away from antifoul, find out whether SeaPen is suitable for your boat.
Send us your boat make, model and location, and our team can assess your vessel and berth and recommend the right SeaPen setup.
Less maintenance. More boating.
DOCKPRO — We make boating easy.
