7 Most Common Ways To Stop Your Boat Sinking


float switch avoid boat sinking

1. Check your float switches and bilge pumps

It never ceases to amaze me how many people own a moored boat but don’t even know what the bilge pump or float switch look like. As an owner, one of the most important things you can do to avoid your boat sinking is to test the automatic float switch is working. To do so, you need to turn all your battery switches to “off”. From there, you will need to get down into the bilge and search around for the pump and float. They’re usually positioned at the very back section of the boat. Sometimes your boat will have three – one at the back, one in the middle and one at the front.

When you activate the float switch, your bilge pump should run until the float is returned to its original position. If it doesn’t, you can then go to the dash and try manually turning your pump on. If it works from there, you’ve likely got a faulty float switch. And if it still doesn’t work, you’ll have to get a multimeter and test the float manually.

2. Inspect your skin fittings

Although this is probably something most people leave to their surveyor – there is no reason why you can’t keep an eye out for any loose skin fittings. Sometimes it is possible that new plastic fittings snap off (I’ve only seen it above to waterline) – and if you do see this it’s a relatively simple fix that can help avoid further trouble and your boat sinking.

3. Check your cockpit drains

Every so often I lift an engine hatch and the cockpit drain is blocked with bottle caps or dirt build-up. While it won’t immediately sink your boat – it is possible that water builds up and gets into places you’ll never know about. Then you’ll have more weight to lug around, or even worse – the water will make its way to the top of the engine as opposed to the drain, and corrode from the outside in.

4. Replace your bellows 

Everybody loves buying a boat with a sterndrive – they’re cheaper and they’re better on fuel. But what does it mean and what on earth are “bellows”?

Bellows are a rubber part designed to keep water out of your boat, and allow the sterndrive to be flexible and steer left to right, up and down. Unfortunately, they don’t last forever, and getting them changed every 2-3 years is in your best interest. If they tear, they can potentially let water in through the back, and sink the boat. Another hot tip is never allow too much barnacle growth. The shells can pierce a hole in the bellows when the boat is turned.

5. Check your propeller shaft seal and bellows

What’s the equivalent of bellows on a shaft drive? Your stern gland! Attached to the fibreglass, you will have a bellows and shaft seal – keeping the water out from underneath. They are usually water cooled from the engine. It’s common for the water cooling fittings to corrode or break off – then causing the seal to overheat and destroy the bellows which may lead to your boat sinking.

check shaft bellows avoid sinking boat

Whilst they do last a lot longer than sterndrive bellows, it’s worth replacing them every 5 years. The shaft seal should be checked while the boat is running (as opposed to stopped) to see if there are any leaks. Just don’t get caught out with a packing gland – as it is normal for them to drip 2-3 times every minute while the shaft is spinning.

6. Carry a timber bung onboard

This is more relevant if you’re doing a long offshore trip – but nevertheless it doesn’t hurt to have a spare timber bung onboard for the most common has size. If you have a sea-cock malfunction, you always know you can blow the water off with the timber bung. They also come in handy when completing service work, for example changing the sea pump impeller.

7. To avoid your boat sinking, test your sea-cocks 

Simply testing your sea-cocks every 6 months will avoid Having them seize. Generally speaking – clockwise is off, anticlockwise is on, but it can depend on how it’s fitted. You will likely have more sea-cocks then you realise – one for each engine, one for the toilet, one for the air conditioning. The list gets larger as the boat gets bigger.

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