Keeping afloatNext - CrewPrevious - Procedures
Keeping afloat after colliding with a waterborne object
The risk of colliding with a floating or waterborne object such as a whale, tree or a freight container is very low. Sadly marine experts believe two centuries of whaling may have reduced whale numbers to 1% of the original population. There are now believed to be as little as 10,000 humpback whales in the North Atlantic were 240,000 roamed (1.5m worldwide). The problem with these, as with all waterborne objects, is keeping watch for them. As they often lie just below the surface it is as good as impossible to see them and they are completely imperceptible at night or in high seas. The risk of colliding with a container is also higher in busy shipping lanes and during winter and spring when storms make it more likely for the highly piled containers to fall or get washed overboard.
An internal manual bilge pump for storm conditions
Most yacht bilge pump arrangements have one manual pump operated from the cockpit and a central electric pump. These do not lend themselves to enduring extreme conditions when a vessel has elected to adopt a 'batten down' strategy and the cockpit may be unsafe. This positioning eliminates the use of the cockpit manual pump.
What to do if you are taking on water and potentially sinking
Boats sink for a number of reasons. Overwhelmed by weather, through faulty hull fitting, lack of maintenance, collision or grounding strikes. A small holing may appear trivial but a five cm hole below the water line will leak three hundred litres per minute. A 10cm hole at the same depth will leak 1,100 litres per minute. Enough to sink a 30ft yacht in 12 minutes. It’s your worst nightmare, you are bringing aboard tons of green water, and you are taking on water faster than the pumps can evacuate it. What do you do now?
Helping prevent bilge pump blockages
Bilge pumps can suck up floating debris that clog up their internal mechanisms and render them useless.
Staunching a hole that may be only addressed externally
If a boat is holed below the waterline and you can’t get at the hole to stop the flow from below decks, you have to get to it from outside. Typically, this is too dangerous a situation to put a crew member in the water as you are only compounding the danger.
Using the engine as an emergency bilge pump
Holed boats take on water very quickly. A 10 cm will leak 1100 litres per minute. Enough to sink a 30ft yacht in 12 minutes. Such an inrush will overwhelm even the best of bilge pumps.