What to do if your Cruising Sailboat is Leaking

Probably the worst emergency at sea is a leak below the waterline. A boat can sink in just 2 or 3 minutes with a major leak. Thus, quick action is needed to assess the damage and take appropriate action. Additionally, big leaks often start out as small ones: therefore, it is essential to check the bilges daily, when at anchor, and hourly when underway. That way, a small leak will be identified early on--hopefully in time to prevent it becoming a big one.

NOTE: This checklist was written specifically for our boat--we had too many thru-hulls (6 below the waterline)--the only weakness we can think of in an otherwise extremely safe offshore sailboat. Because of this weakness, we checked hoses, clamps and seacocks every three months. And, before a passage, we reviewed this list and assigned responsibilities. We had everyone go through the motion of performing their assigned tasks.

Before a passage, lay out for easy grabbing, the headlight, 2 hammers, spare bungs, and 2 pairs of wire-cutting pliers. Also, self-sealing tape, bicycle inner tube, radiator clamps and nut driver to fit.
If water is found in the bilge decide whether:

You have collided with something and holed the boat (container, log, submarine, whale, rock, etc. Alternatively, has the hull-deck seam come apart from falling off a wave? If any of these has happened, you will probably know it.
It is from the propellor shaft–a line has wrapped round it, or some fishing gear–are you in an area known to be fished? If the engine was on, and you hear a change in sound–immediately go into neutral.
It is most likely a thru-hull – there has been no thump or bump. In this case is it a fast leak or a slow leak?
Or it is from a leak in the fresh water tank or hoses. Taste it (yuk)--is it salty or not?

Helmsman alerts all crew and turns on automatic bilge pump and starts pumping the cockpit bilge pump.
If it is known which side of the boat the leak is coming from, helmsman turns the boat immediately to bring that side "up hill".
If thru-hull or shaft is suspect, crew member (A) puts on headlight and grabs hammer, bungs, and wire-cutting pliers and goes into engine room. (A) pulls off the square that closes off the engine, and:

Checks the propellor shaft for leakage. If engine is on, tell helmsman to go into neutral and turn the engine off, then into gear. If leaking, wrap it in stretched bicycle inner tube with radiator clamps.
Closes #12 (frig intake - on floor behind engine on starboard side). This one is below the waterline.
Checks, and if in doubt, closes #5 (engine intake - under drip pan on port side) calling to helmsman to turn off the engine first. This one is below the waterline.
Checks #6 (automatic bilge pump -- forward thru-hull under engine room shelf). If water coming in it, calls to helmsman to turn off the pump, and closes it. This one is at the waterline.
Checks #7 (forward cockpit drain - aft thru-hull under engine room shelf). If water coming in, closes it. This one is at the waterline.
Checks #8 (frig exhaust - port side aft of shelf, 2nd from stern) and closes it. This one is at the waterline.
Checks #9 (heating exhaust - port side aft of shelf, nearest stern, high up) and closes it (if system is on, call to helmsman to turn it off first.) This is above the waterline.

(A) then climbs into lazarette (under helmsman's seat) with hammer, bungs, wire-cutting pliers, and seacock handle extension pipe and:

Checks #10 (engine exhaust - starboard side nearest stern), if leaking calls to helmsman to turn engine off, and closes it. This is above the waterline.
Checks # 11 (aft cockpit drain - starboard side, a bitch to get at). If necessary close it. This one is at the waterline.

Meanwhile, crew member (B) is in the cabin with hammer, bungs, and wire-cutting plyers and:

Checks and closes #13 - (salt water intake for head, washdown pump, and galley – access is under cabin sole in front of door to head). While there, inspects the 3 transducers for leakage. These are all below the waterline.
Checks and closes #1 (head sink drain) and #2 (head outlet overboard). Both are under the head sink, access is through the bottom louvered door. These are below the waterline.
Checks #3 (manual bilge pump – access is through trap behind forward port seatback in main cabin). If leaking, closes it. This one is at the waterline.
Checks and closes #4 (galley sink drain - immediately to the righ tjust inside the cupboard door under the sink.) This one is below the waterline.

Do not give up searching for a leak until the water level in the engine room or cabin drives you out.
If the bow is stove in, close the V-berth door to make a semi-watertight compartment and gain time.
If need be, use the emergency pry bar and hatchet to get at a hole in the hull area.
Depending on the results of the assessment, begin damage control procedures.
Damage control can include:

Driving a wooden bung through a broken skin fitting.
Driving cushions, mattresses, towels into a hole from the inside and buttressing them in place with poles, rods, doors, etc.
Filling a hole with Marine Tex quick-acting epoxy.
Wrapping a split hose with self sealing tape or stretched bicycle inner tube.
Rigging a sail or tarpaulin outside the boat to hold it over a hole in the hull.

Use 2-3 people with buckets, chain-gang like, to help the bilge pumps (if manpower permits). Apparently buckets can move water faster than bilge pumps.
Keep an eye on the water level and batteries so as to be able to transmit a May Day or Pan Pan while you are still afloat and have electricity.
If, and in that case as soon as, it becomes apparent that the damage control procedures are not working, immediately begin abandon ship routine

The Boat is Leaking