In comparison to the topsides, where everything is visible, the bilges can be a mystical world chock-full of equipment, hoses, wiring and other ancillary items. Boat owners who rarely inspect the bilge areas are often surprised when they need to go below to do a repair.
The bilge is among the more important areas aboard any boat. It’s worthy of regular inspections and routine care. Here’s a list to make sure every visit below is time well spent.
Let’s start with offensive smells. Stubborn odors that invade the cabin are often rooted to sour water that’s outboard of the engine and hull stringers in the bilge. If you can’t see everything outboard, tape a small mirror to a scrub brush handle for a better look. Many times, puddles originate from spray that’s leaking from the hullside air boxes, or from clogged drains.
Boats with old-style stuffing boxes constantly drip water into the bilge. Consider installing dripless shaft seals at your next haulout. To be sure, there is nothing wrong with old-school technology, but you need to remember that a leaking stuffing box at the prop shaft or rudderpost admits water that needs to be removed.
Make sure all the limber holes (openings in the stringer where it meets the hull, so water can flow to the bilge pump) are clean and unobstructed of dirt or minute debris. A coat hanger works well to unclog these.
If the bilge pump wears a five-o’clock shadow around its base, then oil or fuel from the engine or generator is likely present in the bilge water. Use a small wet-dry vacuum to draw out as much water as possible before you attempt to address an oily slick in the bilge. Avoid pouring in a bottle of commercial bilge cleaner, which will create a mass of suds with a water hose. It seems like a quick fix, but spraying the mixture of dirty bilge water and soap only spreads that witches’ brew throughout the bilge. This is especially true if the concoction contains smelly diesel fuel, which will be that much harder to remove, as will the fumes that are left behind.
After using the wet-dry vacuum, wipe everything you can reach (including under the engines) with clean rags moistened with Formula 409, Simple Green or a similar cleaner to absorb the oil. Hand dry the area with more clean rags. Only then, after shutting off the bilge pumps, should you consider flooding the area with a biodegradable bilge cleaner and water. Let the soapy solution soak to loosen remaining residue. The longer you leave it working, the better. Then, take the boat out for a ride, flip on the pump switch, and empty the mixture offshore. Never do this at the dock.
When water remains in confined areas where the bilge pump is unable to extract it, consider installing a remote-mounted, self-priming diaphragm pump with the strainer located in the wet area. It is not always possible to get the bilge completely dry, so don’t sweat it. Do the best you can.
Once the bilge is clean, keep an oil-absorbing bilge pillow or sock beneath the engine and elsewhere where water collects. Then, try to be mindful when performing routine maintenance. I keep a bucket nearby when cleaning raw-water strainers to avoid accidentally dumping grass or odorous muck from the baskets into the bilge. The bucket also helps to prevent losing small parts like screens, gaskets and washers by keeping everything in one place.
Never allow shower water to drain into the bilge. The combination of fresh water, soap, body dirt, sunblock and other residue will start to reek in the bilge, and will spread throughout the boat’s interior. Plus, hair could clog a bilge pump.
More bilge area is located in the lazarette. Lift the access hatch to see if moisture has collected on the underside of the hatch. If it appears damp, then leave the hatch off so air can circulate below. Check that the hatch gutter drains are clean and that they drain overboard. Inspect hatch drains each time you wash the boat, and be sure that hose passages are clear and fittings are tight so deck water flows overboard and does not overspill into the bilge.
Also remember the anchor locker, another common source of nefarious odors. Once or twice a season, remove the rode and let it dry out on the foredeck or wherever you can stretch it out to dry thoroughly. If nothing else, leave the hatch open so fresh air can circulate around the rode. Most anchor lockers will have an overboard drain at the bottom of the compartment. Check to make sure the drain is unclogged, or the compartment could fill with water.
On windy days when you are staying dockside, take advantage of the breeze. Open the hatches, doors and drawers throughout the boat. Use the sunlight and fresh air to chase away the moisture that breeds mildew and rust. Move loose gear around so air reaches every surface, and be alert for rust trails on the bottom of the equipment or on the surface where it rests in the bilge. Rust and mildew never sleep.
This article was originally published in the February 2024 issue.
