Cleaning and refurbishing the bilge
How to clean the bilge effectively and safely, remove oil and odour, and prepare it for inspection and painting.
The bilge is the lowest part of the hull interior, where water, oil, fuel and every kind of dirt collect. A clean bilge is not just about looks — it is safety and diagnosis. In a dirty bilge you will not notice a new oil leak from the engine or a leak through a skin fitting, and oily water clogs the bilge pump and its float switch. Regular cleaning lets you catch problems early, before they become serious and expensive.
Before you start, think about safety and the environment. Fumes from fuel and solvents can collect in the bilge, so ventilate it, and wear gloves and goggles when the bilge is oily. CRUCIAL: oily, contaminated water must NOT be pumped overboard — it is an offence and it harms the environment. Collect bilge water in a container and hand it over for disposal at the marina. First remove loose rubbish and larger dirt by hand, and only then start washing.
Oil and grease are removed with a proper bilge cleaner. The most convenient are the emulsifying products — you apply the cleaner, let it work, and then while sailing in a seaway the solution washes the bilge, after which you collect it for disposal. For stubborn dirt use a long-handled brush to reach awkward corners. For picking up the last of the oil, pads and sorbents (bilge pads) work very well, trapping oil while letting water through.
Once the oil is gone, wash properly with water and detergent, and if needed with a product that removes smells and protects against mould. Awkward spots under the engine and tanks are cleaned with brushes and a wet-and-dry vacuum. After washing, dry the bilge thoroughly — damp encourages smells, corrosion of fittings and mould. Only in a clean, dry bilge can its condition be judged reliably.
A clean bilge is a chance to inspect. Check the condition of the skin fittings and seacocks for signs of leaks and corrosion, check the hose clamps, the state of the bilge pump and its float switch, and that the limber holes through which water runs down to the pumping point are clear. Blocked limber holes leave water standing in sections of the hull that the pump cannot reach. Clearing those passages is an important part of the job.
If the bilge is heavily stained or the old coating is flaking, it is worth considering painting it. After thorough cleaning, drying and light keying, apply bilge paint (usually single-pack, resistant to oil and water), normally in a light colour. A light coating makes it far easier to spot new leaks later — a drop of oil or a run shows up at once against white. Painting also makes future cleaning easier.
Finally, equip the bilge with things that keep it clean: an oil-absorbing pad under the engine and, optionally, an automatic pump with a float switch in case of a leak. Regular checks — ideally on every longer stay aboard — and a quick reaction to any oil or water that appears keep the bilge in excellent condition with minimal effort. A clean bilge is the calling card of a well-kept yacht.
Material prices — products and options
Indicative prices in EUR (incl. VAT), as of July 2026. Products widely available in Europe; prices depend on the shop, the pack size and consumption. The links lead to example shops that ship across the EU. Dollar amounts are converted at 1 EUR = 1.1622 USD (ECB, 7 September 2026) and rounded — treat them as a rough guide, not a price in a US shop. Imperial values in brackets are conversions of the metric figure.
Degreasers and bilge cleaners
- Yachticon — Wonder Bilge
emulsifying bilge degreaser, 0.5 l (0.1 US gal)€18–26 (≈$21–30) - Star brite — Bilge Cleaner
biodegradable bilge cleaner, 950 ml (32 fl oz)€16–24 (≈$19–28) - Yachtcare / Presto — bilge cleaner (canister)
degreasing concentrate, budget option in a larger pack€12–20 (≈$14–23)
Sorbents and oil pads
- Oil-absorbing bilge pads
soak up oil and fuel residues but not water, pack€15–45 (≈$17–52) - Absorbent bilge sock
floating absorbent to keep permanently in the bilge€8–20 (≈$9–23)
Brushes, sponges and accessories
- Long-handled brush
access to the bottom of the bilge under the sole€10–25 (≈$12–29) - Sponges and absorbent cloths (set)
for mopping up residual water and cleaning€5–14 (≈$6–16)
Drying the bilge — pumps
- Hand bilge pump
about 20 l (5.3 US gal)/min, 25 mm (0.98 in) connection€20–40 (≈$23–46) - Rule — automatic bilge pump 500 (12 V)
with a sensor/float switch, for smaller boats€90–140 (≈$105–163) - Wet vacuum cleaner
for removing oily water and sediment€40–120 (≈$46–139)
Disposal and safety
- Canister for oily water
sealed container for handing over for disposal€8–20 (≈$9–23) - Nitrile gloves and safety goggles
protection when working with degreasers€6–16 (≈$7–19)
Finishing and odour
- Bilge paint (light colour)
resistant to moisture and fuel, makes leaks easier to spot€20–45 (≈$23–52) (approx.) - Star brite / Yachticon — mould and odour treatment
neutraliser for smells and fungus in the bilge€10–20 (≈$12–23)