Bilge Pumps: When To Install And Why

A bilge pump is an essential piece of safety equipment for any boat owner. While not required by law, bilge pumps are designed to remove water that collects at the bottom of the inside of the hull, known as the bilge, and prevent the boat from sinking. This water can enter the boat through a number of ways, including rain, leaks, splashes, cleaning, or built-in coolers that drain into the bilge. Given the importance of this function, it is critical to understand when and how to use a bilge pump.

The importance of bilge pumps

A bilge pump is a crucial piece of safety equipment on a boat. Its function is to remove water that collects in the bilge, which is the bottom of the inside of the hull. While not required by law, a bilge pump is essential to prevent a boat from sinking.

Water can collect in the bilge in several ways. It could be rainwater, water from spray or waves, or water from cleaning or built-in coolers. A bilge pump is necessary to regulate water levels inside the boat to prevent too much water from gathering at the bottom. This is especially important as water pooling inside a boat can lead to dangerous and costly problems, including corrosion and sinking.

For example, a v-hull boat will have bilge pumps in enclosed areas such as the engine compartment, while a pontoon boat will have a bilge pump in storage compartments to keep those areas dry. By keeping water out of the lower parts of the boat, bilge pumps help to lessen the chance of damage due to corrosion.

Bilge pumps are also important because they can provide warning that a boat is taking on water when it shouldn't be. If there is a small hole in the boat, the bilge pump can pump the water out as fast as it is entering the boat, giving the crew time to get back to safety.

There are two main types of bilge pumps: manual and automatic. Manual bilge pumps are a good option for small recreational boats such as kayaks and canoes, as they are handheld and easy to use in non-motorized vessels. Automatic bilge pumps, on the other hand, are activated by water levels in the bilge and are perfect for maintaining low water levels.

When it comes to the number of bilge pumps, it is recommended to have multiple bilge pumps on board for safety reasons. This is especially important for larger boats, which often require multiple bilge pumps. Having multiple bilge pumps helps to maintain the overall health of the boat and ensures that the boat does not fill completely with water if one pump fails.

In terms of maintenance, it is important to regularly check the functionality of a boat's bilge pump to ensure optimal performance. This includes checking the wiring and float switch, outlet hose, impeller, and filters. It is also crucial to keep the bilge area clean and free of debris, which could clog the pump or foul it.

In conclusion, bilge pumps are an essential component of a boat's safety system. They help regulate water levels, prevent corrosion and sinking, and provide warning of potential issues. By understanding the importance of bilge pumps and performing regular maintenance, boat owners can ensure the safety and longevity of their vessel.

Manual vs automatic bilge pumps

A bilge pump is a key piece of equipment for any boat owner. Its function is to remove water that collects in the bilge, which is the bottom of the inside of the hull. While not a legal requirement, it is essential for preventing your boat from sinking.

There are two main types of bilge pump: manual and automatic.

Manual bilge pumps require physical action to operate. They can be portable or fixed, and discharge between 25 and 100L/minute of water. They can be self-priming, developing suction and priming themselves when dry, and can be single or double-action, using one or multiple diaphragms. Larger manual pumps can be rated at 50 gallons per hour (GPH).

Automatic bilge pumps, on the other hand, are triggered when the bilge water reaches a certain level. A float rises with the water until it activates the pump when the water is high enough. These pumps are fixed and submersible, and can easily be positioned at the bottom of the hold. They are also very efficient, pumping between 25 and 160L of water/minute.

There are pros and cons to both types of pump. Manual pumps give you more control and can be useful in an emergency if your electrical system fails. Automatic pumps, on the other hand, require less effort and can be left to activate without intervention.

Many boat owners opt to use a combination of both types of pump. A smaller automatic pump can be used to pump out rainwater and other incidental water, while a high-capacity manual pump can be used to handle more serious situations. This strategy ensures that you are prepared for any eventuality.

When choosing a bilge pump, it is important to consider the size of your boat, the amount of water it typically collects, and the distance and height the water must be moved. It is also crucial to regularly inspect and maintain your bilge pump to ensure it is functioning properly. This includes checking for debris, testing the float switch, and verifying that all wiring connections are watertight.

Bilge pump maintenance

The bilge pump is a crucial piece of equipment on a boat, responsible for removing water that collects at the bottom of the inside of the hull. While not required by law, it is essential for keeping your boat afloat. Regular maintenance is therefore important to ensure your bilge pump functions efficiently when needed. Here are some key tips for bilge pump maintenance:

Cleaning and Debris Removal

One of the most important maintenance tasks is to keep the bilge area clean and free of debris. Over time, leaves, twigs, sediment, and other types of construction debris can accumulate in the pump, leading to clogs and reduced effectiveness. Periodically inspect and clean your bilge pump to prevent blockages and ensure optimal performance. Remove any visible debris from the bilge area by hand and use a wet/dry vacuum to clean harder-to-reach areas.

Testing Sensors and Switches

Many modern bilge pumps have internal sensors or float switches that detect water levels and automatically activate the pump. It is important to test these sensors regularly to ensure they are functioning correctly. This can be done by manually triggering the sensor or simulating water ingress. Check the function of the float switch, which can get corroded over time. If your bilge pump has an automatic float switch, test its operation by putting a few gallons of water in the bilge and observing if the pump activates on its own.

Backup Features

In addition to internal sensors, some bilge pumps have backup features such as cycle modes that alternate between pumping and resting to prevent overheating and extend the pump's lifespan. It is important to familiarise yourself with these backup features and any manual activation mechanisms in case of an emergency.

Maintenance of Strainer and Hoses

All bilge pumps should have a strainer to protect the pump from debris. Check the strainer regularly for debris, hair, and other bilge dirt. Also, inspect the discharge hose for any clogs or leaks. If the hose is a corrugated type, consider replacing it with a smooth-wall hose to increase the flow rate. Ensure the hose is securely clamped and that the discharge thru-hull fitting is well above the waterline to prevent water from siphoning back into the bilge.

Electrical Connections

Most bilge pump failures can be traced to corroded electrical connectors, so it is important to inspect all wiring and connections. Ensure they are properly sealed and installed well above the normal accumulation of bilge water. Replace any connections made with electrical tape and household twist-on connectors with proper marine-grade heat-shrink connectors.

Bilge pump installation

A bilge pump is a key piece of equipment found on most boats. It is not required by law, but it is essential to prevent your boat from sinking. Its function is to remove water that collects in the bilge, which is the bottom of the inside of the hull.

Where to Install a Bilge Pump

At least one pump or bilge pump pickup should be installed at the lowest point in the bilge. Larger boats should have one in each enclosed area that can retain water. Discharge outlets need to be a minimum of eight inches above the waterline.

All bilge pumps should be easily accessible for inspection and maintenance. If the pump is located in a spot that’s inaccessible or hard to reach, such as below the engine on a sterndrive boat, consider relocating it.

How to Install a Bilge Pump

Pumps must be fastened down and not placed in the bilge unrestrained, as they will suck air and burn out if they fall over. Brackets are available that attach to a stringer or other vertical feature, or you can epoxy bolts to the bottom of the bilge to serve as mounting studs.

Float switches must also be fastened. The discharge fitting must never go below the waterline. If the fitting is through the transom, ensure it is high enough not to submerge when the stern squats. If it is through the side of the hull, it must be high enough to remain above water at the deepest angle of heel.

Use a thin-wall fitting to minimise restriction and a smooth-bore hose to increase pump output. Bends and long runs reduce pump output, so make the hose run as straight and as short as possible.

It is essential to get the pump wiring out of the bilge as quickly as possible. Run the wires up and secure them so that they do not sag into the bilge water.

Pump Wiring and Powering

Do not skimp on wire size. Consult the ABYC Wire Size Table to determine the appropriate wire for your pump and length of wire run. Use butt connectors and heat shrink to assure a good mechanical and electrical connection.

Connect an automatic bilge pump directly to the battery, not through the distribution panel, so that it is not turned off when you power off the boat. Fuse the positive side, with the fuse as close to the battery as possible.

Pump Maintenance

Make sure all pumps, float switches, and strainers are easily accessible for routine maintenance and emergency repairs. Remove, disassemble, and inspect pumps at least twice a year for broken or worn parts. Check that all pumps are firmly mounted, paying particular attention to the mounts themselves, which may develop hairline cracks.

Keep the bilge clean, as no pump can overcome a bilge choked with trash. Make sure all intake strainers are securely fastened in place and clear them of any gunk that may have accumulated.

When to use a bilge pump

A bilge pump is a crucial safety feature of a boat. It is used to remove water that collects in the bilge, which is the bottom of the inside of the hull. Water may collect in the bilge due to rain, leaks, splashes, cleaning, or built-in coolers that drain into the bilge. While a small amount of water in the bilge is normal, a large amount of water can cause dangerous and costly problems. Therefore, it is important to use a bilge pump to regulate the water levels inside the boat and prevent too much water from pooling at the bottom.

Bilge pumps can be activated manually or automatically. Manual bilge pumps are typically used for small recreational boats such as kayaks and canoes, and they must be turned on when needed to drain the bilge. Automatic bilge pumps, on the other hand, are activated by water levels in the bilge and are perfect for maintaining low water levels. These pumps have an automatic switch that turns on when the water reaches a certain level.

It is important to regularly inspect and maintain your bilge pump to ensure it is working properly. Before heading out on the water, you should test the bilge pump by pouring a few gallons of water into the bilge to ensure it activates and removes the water. You should also check the wiring and float switch, outlet hose, impeller, and filters for any signs of damage or clogging.

In addition to regular maintenance, there are several situations in which you may need to use a bilge pump:

• Incidental Water Collection: Bilge pumps are typically used to remove incidental water that collects in the bilge. This can include rainwater, water from spray or waves, wash-down water from cleaning the boat, or water from built-in coolers that drain to the bilge.
• Minor Leaks: Bilge pumps can also handle minor leaks, such as water dripping from the shaft gland on an inboard boat.
• Emergency Situations: While a bilge pump may not be large enough to prevent a boat from sinking in a catastrophe, such as a large hole in the hull, it can buy you time to repair or mitigate the leak, call for assistance, or prepare to abandon the boat in an orderly manner.
• Warning of Water Ingress: A bilge pump can also warn you that your boat is taking on water when it shouldn't be. If there is a small hole in your boat, the bilge pump can pump out the water as fast as it is entering the boat, giving you time to get back to safety.

It is important to note that a bilge pump should not be solely relied on to keep your boat afloat. In an emergency situation, it is always best to seek help if your vessel is taking on water.

Frequently asked questions