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How to Keep a Boat from Sinking
Simple Maintenance Can Help Keep a Boat Afloat

How to Keep a Boat from Sinking


Picture a sinking boat.  Not an ocean liner but a bowrider or cabin cruiser.  Often the picture is a boat that’s run into something and is going down in the middle of the lake while people scramble to put on life jackets. 


Well, that’s certainly dramatic but roughly two-thirds of all boats sink at the dock, often when there is no one around.  According to a study of insurance claims by the Boat Owners’ Association of the United States (BoatUS), 69 per cent of boats sink at the dock or mooring and only 31 per cent sink while underway.


Delving into the survey brings other interesting facts to light.  Of all the boats that sink when moored, nearly 40 per cent are the result of small part failures… or when several small things add up to a flow that the bilge pump can no longer sustain… things like small cracks in the sterndrive bellows, raw water hoses, water fittings in the hull, or the failure of a bilge pump float. 


Boats that sink underway generally hit something… a reef, another boat, a channel marker, a log or something similar. 


With one exception, boats are not often sunk by water splashing in over low transoms because of changes in the design of the boat (splash wells).  However, a boat that is tied up with its stern to the waves is very susceptible to swamping.


To prevent a sinking, here are ten tips from the boat owner's group:


Inspect sterndrive bellows annually and replace every three to five years. The shift bellows is usually the first to fail.


For inboard powered boats, check the stuffing box every time you visit the boat, and repack every spring.  Don’t just tighten down the nut.


Replace raw water hoses the moment they indicate wear - such as when small cracks appear or they feel "spongy" when squeezed… same with rusty hose clamps.


Replace the engine cooling system impeller every two to three years.


Inspect the boat's cockpit and livewell plumbing - again look at hoses, clamps, and cracked or broken fittings. Make sure you can inspect all such plumbing, and if you can't, install inspection ports to make the task easier.


Each season take a hard look at all the fittings that are below the waterline, hoses, and clamps.


Don't forget the drain plug.  Someone always forgets the drain plug, and keep in mind that it’s not just forgetting to put it in, they also fail.


Keep a good lookout and ask guests to help keep their eyes peeled for deadheads. If you've grounded or hit something, consider a short-haul to inspect the bottom or drive gear.


Always pull trailerable boats from the water when storms are forecast. These boats generally have too little freeboard to stand up to any kind of wave action.


Dock line management systems that keep the boat centered in its slip can prevent snags that sometimes lead to a sinking.

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