The Unique Smell Of Boat Docks: A Curious Conundrum

Boats that are regularly used rarely smell. However, boats that are shut up for long periods, especially in hot and humid conditions, can develop a powerful stink. The accumulation of human sweat, mould, mildew and diesel fumes can cause an unpleasant odour. In addition, boats with toilets have holding tanks that, if not properly maintained, can become a source of noxious smells.

Sewage, rot, and mould

Sewage

The toilet and related systems are often the primary sources of sewage odours on boat docks. Holding tanks, hoses, and head compartments can emit foul smells if not properly maintained. To prevent this, regular pumping and cleaning of the holding tank are essential. It is also crucial to use appropriate treatments, such as bioactive or enzyme treatments, to manage waste and control odours effectively. Additionally, regular inspection and maintenance of hoses, seals, gaskets, and impellers in the sanitation system are necessary to prevent leaks and odour permeation.

Rot

Rotten woodwork and upholstery can contribute to the unpleasant smell of a boat dock. Over time, woodwork may rot due to water damage or mould and mildew growth. To address this, it is important to regularly inspect and replace any rotten woodwork. Upholstery and cushions should also be cleaned or replaced, as they can retain body sweat and other odours. Allowing proper ventilation and air circulation can help prevent the accumulation of stale odours and promote drying.

Mould

Mould and mildew thrive in damp and humid environments, making boat docks susceptible to their growth. To combat mould and mildew, regular cleaning with mould-inhibiting solutions is essential. Bleach and water mixtures are commonly used to wash down affected areas. Additionally, products like tea tree oil, clove oil, and commercial mould and mildew stain removers can be effective in treating and preventing mould growth. Proper ventilation and dehumidification are also crucial in preventing mould and mildew from taking hold.

Fuel tank leaks

Signs of a Fuel Tank Leak

• Overwhelming smell of gasoline in the cabin: While the fuel system is not airtight, you should not smell any fumes inside the boat. If you constantly smell gasoline while on board, it could indicate small leaks or a more severe issue.
• Significant drop in the fuel gauge: Keep an eye on your fuel gauge, especially when the boat is stationary. If you notice a rapid decrease in fuel level, it could indicate a fuel tank or fuel line leak.
• Puddle of fuel under the tank: Check for translucent puddles under your fuel tank. To confirm, place cardboard or newspaper under the tank to identify any leaks.

What to Do if You Suspect a Fuel Tank Leak

• Do not attempt to fix it yourself: Unless you are a skilled mechanic, it is best to leave fuel tank repairs to professionals. Fuel leaks are highly flammable and can lead to fires or explosions.
• Take your boat to a mechanic: A trained mechanic will be able to pinpoint the exact cause of the leakage, perform necessary repairs, and replace components like fuel lines and seals if needed.
• Do not drive with a fuel leak: Driving with a fuel leak is not recommended due to the risk of fire or explosion. Even a small amount of fuel landing on a hot component can potentially ignite.
• Address the issue promptly: The sooner you address a fuel leak, the faster you can safely get back on the water. Delaying repairs may lead to more severe problems and put yourself and others at risk.

Diesel fumes

Diesel exhaust is a result of incomplete combustion in diesel engines. It contains carbon monoxide, which is a highly toxic gas that can be dangerous even at low concentrations. The US Environmental Protection Agency (EPA) has established an inhalation reference concentration (RfC) for diesel particulate matter (DPM) to estimate safe exposure levels.

The odour of diesel fumes is often associated with waiting behind an eighteen-wheeler or at a train station. The smell is a strong indicator of the presence of diesel exhaust, which can infiltrate indoor spaces and pose potential health risks. It is important to investigate and control the source of diesel fumes to mitigate exposure and potential health issues.

Nitrogen oxides (NOx) are another significant component of diesel exhaust due to the lean-burning nature of diesel engines, high pressures, and temperatures during combustion. Real-time readings of NOx concentrations are measured during diesel exposure assessments to understand the extent of emissions.

Volatile organic compounds (VOCs) are also adsorbed onto the carbon particles produced during diesel combustion. These compounds can be measured using photoionization detectors or gas chromatography for specific VOC identification.

Holding tank maintenance

Preventing Odours

• Ensure your holding tank system has adequate airflow. Eliminate any low spots in vent lines that would restrict airflow. Aerobic bacteria (which break down waste) require oxygen to live and function.
• Avoid using detergent, bleach, dish soap, or other cleaning agents in the holding tank.
• If using a chemical treatment, use one that is formaldehyde and bromine-free. This will allow aerobic bacteria to live and function properly in the tank.
• Check the hoses, seals, gaskets, and impellers in your sanitation system regularly and fix any issues immediately.
• Pump out the tank before it is full to prevent overflow.

Shocking the Tank

• In the spring, or when you haul your boat out for the winter, it is recommended to shock your tank to clean and descale it.
• Add a shock treatment a week before the last pump-out while the boat is still in use. This will help descale the walls and ceiling of the tank.
• You can also shock the tank mid-season if you notice an odour building up.

Treating Waste

There are four methods for treating waste in your holding tank:

• Chemical Treatment: Chemical treatments are the most common and kill bacteria immediately. They are effective at controlling odours but are not designed to dissolve waste and are not environmentally friendly. Be sure to use a treatment that does not contain formaldehyde or bromine, as these are toxic.
• Bioactive Treatment: Bioactive treatments contain live aerobic bacteria that break down waste, reproduce, and crowd out anaerobic bacteria that produce odours. They are environmentally friendly and cost-effective in the long run. However, they require a well-ventilated tank free of residuals from previous chemical treatments.
• Enzyme Treatment: Enzyme treatments accelerate the digestion of organic materials and neutralise odours. They have low toxicity and must be added regularly. They are sensitive to chemicals, heat, and cold, making them difficult to manage accurately.
• Nitrate Treatment: When there is little oxygen present in the tank, bacteria derive oxygen from sulfates in the waste, producing hydrogen sulfide gas (the odour associated with sewage). When nitrates are introduced, they provide an alternative source of oxygen for the bacteria, resulting in the production of odourless nitrogen gas. Nitrate treatment is environmentally friendly and effective at eliminating odours. However, it requires a tank free of residuals from other products.

Other Tips

• Use biodegradable marine toilet paper to ensure it breaks down properly and doesn't cause blockages.
• If you notice a leak, fix it as soon as possible. Leaks can cause sewage to spread throughout the boat, permeating clothing, bedding, and other fabrics. It can take months to get rid of the smell.
• Calculate the number of person-days your tank can handle to manage your tank and plan pump-outs accordingly.

Boat upholstery

Boat docks can smell like a lot of things, from sewage to mildew, and even propane. But what if you want your boat to smell like the open sea and nothing else? Well, that's where boat upholstery comes in.

When selecting boat upholstery, it's crucial to choose a material that is specifically designed for marine use. Marine-grade vinyl, for instance, is a popular choice due to its durability and water-resistant properties. It is resistant to fading, cracking, and degradation caused by exposure to sunlight, saltwater, and other environmental factors.

But why stop at odour prevention? With boat upholstery, you can also elevate the aesthetics of your vessel. Sunbrella, for instance, offers a large collection of beautiful, quality upholstery fabrics to choose from, allowing you to create a look that's all your own. Their fabrics are UV protective, fade-resistant, stain-resistant, and easy to clean—perfect for maintaining that "just sailed out of the showroom" look.

So, if you're looking to keep your boat smelling and looking fresh, consider investing in some high-quality boat upholstery. It might just be the difference between a pleasant cruise and a putrid voyage.

Frequently asked questions