280 seamanship secrets
Handle Flooding Emergencies with M.A.T.E.
It’s been a fi ne boating day, and you’re nestled in the perfect anchorage, just you
and your beauty. With a mug o’ rum and a fi ne imported stogie, it just doesn’t
get better than this. You stare lazily up at the canopy of twinkling prisms above
your head. Every so oft en a shooting star streaks across the gilded background.
Ah, this is the life! Th irty minutes later, you pick yourself up and meander down
the companionway. You never make it past the last step...
You tumble onto your hands and knees in 6 inches of ice cold, brackish water.
It’s pouring in—but from where? You push the switch on the cabin lights and
nothing happens. Where’s the damn fl ashlight? You desperately pull out drawer
aft er drawer. Contents spill into the salty liquid, which is already creeping steadily
above your ankles. Finally you fi nd a small fl ashlight, tear away the engine cover,
and shine the light at the raw-water seacock. It’s closed and the hose looks intact.
Sweeping the lantern from right to left , you locate the source of the problem.
Th e sink overboard discharge hose has blown off its seacock. Water gushes
in through a 1-inch hole, 1 foot below the waterline. Every hour, you’re taking
on 1,200 gallons of seawater. In just 60 minutes your boat’s displacement will
increase by 10,200 pounds!
Grabbing the seacock handle, you push it forward to shut it off , but nothing
happens. Desperately fl ailing at the frozen fi tting, your skin and fi ngernails tear
away, bloodying the brackish water below. Where did you stow the hammer?
Turning back to the cabin, the lantern begins fl ickering, blinking once, twice ...
then it dies. You push the button on and off. Nothing. Now you have no lantern,
no batteries, and no hammer.
Insurance companies claim that 50% of vessel sinkings occur to moored or
anchored vessels. Undersized bilge pumps rarely keep up with water fl ooding in
from stuffi ng boxes, blown seacock hoses, or broken gate valves. Most emergencies
result from little things overlooked or ignored. In our scenario above, the deadly
domino eff ect turned an easy-to-solve problem into a serious emergency.
Th e typical production boat has six to eight holes drilled below her waterline,
with average diameters of^1 / 2 inch, 1 inch, or 2 inches. Th ese through-hulls accom-
modate the engine raw-water intake, sink and shower drains, cockpit scupper
drains, and instrument impellers. Th e graph shows hourly water-fl ow rates through
a 1-inch-diameter hole at various depths below the waterline.
Each gallon of seawater fl owing into your hull adds about 8.5 pounds to your
displacement. For a real eye-opener, multiply this by the fl ow rate per hour. With
enough water or liquid sloshing fore and aft or left to right, you can capsize. Big
ships have this problem unless they keep their liquid cargo tanks fi lled. You need
to have an attack plan in place before a fl ooding emergency strikes. Start with a
map of all hull penetrations above and below your waterline.