How to Reduce Your Environmental Impact on the Water
Most boaters love the water. That is why they boat. But the uncomfortable truth is that recreational boating can have a significant environmental impact if we are not thoughtful about how we operate. The good news is that the steps to reduce your footprint are practical, affordable, and in many cases make your boating experience better, not worse.
Anti-Fouling: What Goes on Your Hull Matters
Anti-fouling paint prevents marine growth from attaching to your hull, but the chemicals that make it effective can be harmful to marine ecosystems. Tributyltin (TBT), once the industry standard, was banned globally due to its devastating effects on marine organisms. Most anti-fouling paints now use copper-based biocides, which are less harmful but still release heavy metals into the water.
The emerging alternative is silicone-based non-toxic coatings. These work by creating an ultra-smooth surface that marine organisms struggle to grip, rather than poisoning them. The Australian anti-fouling market is substantial and growing (valued at approximately USD 7.4 billion globally in 2025 and projected to reach USD 12.8 billion by 2031), which means non-toxic options are becoming more accessible and cost-competitive every year.
For trailerable boats that are stored on land between uses, fouling is far less of an issue. The hull dries between outings, naturally discouraging growth. This is one of the underappreciated environmental benefits of a trailerable vessel.
Sewage: A Bigger Problem Than You Think
The impact of boat sewage on water quality is often underestimated. According to NSW Roads and Maritime Services, the raw sewage discharged by a single weekend boater is equivalent to the treated sewage output of 10,000 people. That statistic bears repeating: one boat, one weekend, the bacterial load of a small town.
Regulations vary by state but are strictest in environmentally sensitive areas. On the Great Barrier Reef in Queensland, untreated sewage must never be discharged, and even treated sewage can only be discharged more than three nautical miles from the reef. Western Australia designates three distinct sewage discharge zones with escalating restrictions closer to shore.
The simplest solution for day-use vessels is to use shore facilities before and after your trip. For boats with heads, invest in a holding tank and use pump-out stations. It is a minor inconvenience that makes a major difference to water quality.
Plastic and Marine Debris
Marine debris is one of the most visible and distressing environmental problems on Australian waterways. According to the Department of Climate Change, Energy, the Environment and Water (DCCEEW), 75 percent of marine debris in Australian waters is plastic. Globally, between 6 and 12 million tonnes of plastic enter the oceans every year.
The consequences for wildlife are severe. CSIRO research projects that plastics ingestion may reach 95 percent of all seabird species by 2050. DCCEEW has listed marine debris as a key threatening process for Australian fauna under national environmental law. Every piece of plastic that blows off a boat, every fishing line that is not retrieved, contributes to this crisis.
Practical steps are straightforward. Secure all loose items before getting underway. Use reusable containers instead of single-use packaging. Retrieve all fishing line and tackle. And if you see debris in the water, pick it up, even if it is not yours. A mesh bag attached to a cleat makes collection easy.
Fuel and Emissions
Fuel spills are an often-overlooked source of water contamination. Overfilling tanks, careless refuelling, and engine leaks all contribute. Even small amounts of fuel create a visible sheen on the water and are toxic to marine life. Use an absorbent collar around the fuel vent during refuelling, fill slowly to avoid overflow, and check engine hoses regularly for deterioration.
Of course, the most effective way to eliminate fuel-related contamination is to eliminate fuel entirely. Electric propulsion produces no fuel spills, no exhaust emissions, and no oil in the bilge water. It is the cleanest possible way to be on the water.
Every Decision Counts
Sustainable boating is not about perfection. It is about making better choices consistently. Choose non-toxic anti-fouling when you can. Manage your sewage responsibly. Secure your rubbish. Maintain your engine. And if you are in the market for a new vessel, consider one that eliminates the biggest environmental impacts by design.
Cat Cruisers’ electric amphibious catamarans produce zero exhaust emissions on the water, are trailerable (minimising anti-fouling needs), and are designed for the kind of low-impact boating that lets you enjoy Australian waterways without degrading them. Learn more at catcruisers.com.au or contact us at catcruisers.com.au/contact.