Flooding: Find It, Plug It, Pump It

When water is coming in, panic wastes the seconds that matter most. The drill has a strict order: find the ingress, stop or slow it, then pump out what's already aboard. Pumping first is a losing game — recall from earlier cards that you always treat the source before the symptom. And the source is almost never a hole punched in open hull: the most common floods come from through-hull fittings — a failed seacock, a burst hose, or a sheared skin fitting for the engine intake, heads, or log impeller.

Speed matters because ingress is brutal. A hole roughly 25 mm (1 inch) across sitting about 0.3 m (1 ft) below the waterline admits on the order of 30 US gallons (110 litres) per minute — far more than most electric bilge pumps can shift. The deeper the hole and the bigger its area, the faster it floods, so a small leak near the keel can beat you while a larger one near the waterline is manageable.

The cheapest lifesaver aboard is a set of soft-wood tapered plugs (bungs), ideally one tied to every seacock so it's found by feel in a flooding, dark bilge. Hammer the bung into the failed fitting or a hull puncture; the wood swells as it wets and seals tighter. For a larger breach, a collision mat — a sail, cushion, or purpose-made cloth dragged over the outside so water pressure holds it against the hole — buys time.

Only once ingress is checked do you win the pumping battle. Run electric and manual pumps together, but remember the old truth: the best bilge pump is a frightened crew with a bucket — a bucket brigade often moves more water than the built-in pumps. If water still gains, that's your trigger to send a Mayday (from the previous card) while you can still work the boat.