Leaks and flooding at the berth

Water ingress on a boat: searching in the right order

Seeing water above the floorboards makes everyone want to act at once. Even so, take a minute to watch how fast the level rises. A slow rise leaves time for a calm search. A fast one means two jobs at the same time: one person pumps while another searches. Stop the engine briefly if you can, because without its noise you will often hear where water is trickling or hissing in.

Work from the most likely sources to the least likely. Top of the list are the engine's raw water circuit, the stern gland and the rudder, followed by the heads and galley seacocks, the log and depth transducers and the cockpit drains. Only after that come the hull itself, the keel bolts and deck fittings. Under sail with heel, water can also come in through the anchor locker, the chainplates or a toilet without an anti siphon loop, which draws seawater in as the boat leans.

It helps to have a plan in the chart table long before you need it: a sketch of every through hull, where it is and how to get at it. Otherwise, in the dark with water in the saloon, nobody finds the seacock behind the third drawer.

How to stop a leak on a boat, from inside and outside

The deeper a hole sits below the waterline and the bigger it is, the harder water forces its way in. So any reduction counts, even if the leak still weeps afterwards. A split hose is dealt with first by closing its seacock. If the valve or the skin fitting itself has failed, drive in a softwood bung with light taps. Cracks and ragged holes can be packed with cushions, towels or a piece of neoprene, held hard with a board and a wedge against a bulkhead or floor. Underwater epoxy putty cures on wet surfaces and will seal smaller damage.

From outside, water pressure is on your side. A collision mat, or a headsail or cockpit cover in its place, is hauled under the hull with lines and secured over the hole. The water then presses the fabric against the hull and largely seals it. This works best with little speed through the water and several pairs of hands on deck.

If the damage is close to the waterline, a change of tack can make a real difference. Sail so that the damaged side is uppermost, and the pressure on the hole drops sharply, buying time for a proper repair.

Seacock care: checks, materials and what to replace

Most seacocks aboard modern boats are ball valves with a lever. With the lever in line with the hose the valve is open, across the hose it is closed. Work every one of them several times a season, at the very least at launch and at lift out. A valve that has not moved for years will be seized when you need it, or the handle will snap off.

Pay attention to the metal. Seacocks and skin fittings in bronze or dezincification resistant brass are made for seawater, ordinary brass from a hardware shop is not. In salt water it loses its zinc and turns porous, often showing a pinkish tinge. Do not mix different metals at one through hull either, or galvanic corrosion will eat the weaker part. Hoses below the waterline should be reinforced and rated for seawater and, as a rule of thumb, secured with two stainless steel clips.

When you leave the boat, close the seacocks for the heads, the galley and the engine. The cockpit drains stay open so that rain can run away. Make it the last thing you do before locking up and you will not forget it.

Bilge pump capacity and maintenance

Good pumping arrangements come in layers. An electric pump with a float switch works on its own. A manual pump works without power and should be operable from the cockpit with the washboards in. Add two stout buckets, because a person with a bucket moves a surprising amount of water in the first few minutes.

The flow figure on the box of an electric pump is usually measured with no lift and a short hose. On board, with a rise to the outlet, a long hose and a non return valve, the same pump often manages much less. Keep the bilge clean, as hair, labels and wood shavings block the strainer exactly when it matters. At the start of the season lift the float switch by hand and check that the pump starts.

There is a well known last resort when nothing else keeps up. With the engine running, close the raw water seacock, pull off the intake hose and hold it in the bilge with a strainer over the end. The engine's pump then draws bilge water and cools the engine with it. It only works as long as the hose never runs dry and no debris gets into the cooling circuit.

Flooding at the berth and when to call for help

Many boats fill up while nobody is aboard. Blocked cockpit drains let a heavy downpour flood the cockpit, and snow pushes the stern down until drains and exhaust are below water. Frost splits water filled strainers and valve bodies, and the crack only shows after the thaw. A bilge alarm that reaches your phone and a neighbour on the pontoon who looks in now and then are the best protection at the berth.

At sea, the call depends on the situation. If the leak is under control but you need a pump or an escort, a Pan-Pan urgency call on channel 16 is right. If the water keeps rising despite everything, there is grave and imminent danger, and you send the DSC distress alert followed by a Mayday voice call. Get everyone into lifejackets and make the liferaft ready, but leave the boat only when she truly cannot be kept afloat.

Frequently asked questions