You might be a sailor earning a daily wage with your boat or a person in love with the seas. You might like to spend some quality time on the water, with the breeze blowing against your ears and the blue horizon complementing the Sun. Sailing has been one of the most adventurous activities and sailors have always enjoyed the time on their boats or ships, alone with the vast water body. This is where bilge pump comes into play.

As majestic as it gets, the experience requires some basic amenities to work in sync like suitable weather for going out on a voyage. You certainly would not want to take your boat on a rough sea. And also, a properly working boat or ship. There are a few boat components that should be running flawlessly to result in a good voyage. One such component is a bilge pump.

 A bilge pump is an essential part of a boat or a ship. 

The bilge pumps save the boat from numerous potential accidents. Bilge pumps are a type of marine water pump, which can be found on ships of all sizes. The lower-most section of the boat, under the waterline, might collect water and oil. This part is known as the bilge well and sailors often find it impossible to prevent water and oil from entering the bilge well.

In the big-sized watercraft, the bilge well might get flooded due to the water or oil coming out of the drainage systems or the machinery spaces. On the other hand, in the case of smaller boats, the bilge pump might get flooded due to rain or a huge wave lashing on the boat. Moreover, the other sources from which water might enter the bilge are the propeller shaft packing gland, a portlight that has been leaking, and molten ice in the icebox.

The buyer should be aware of the fact that there are several ways that the boat can be affected by an overflowing bilge. The boat might get destabilized or might lift the spilled over fuel and drive it all over the bilge. This can affect the electric wire insulation and lead to the formation of osmotic blisters in the boat hulls made up of fiberglass. Moreover, a filled-up bilge might as well lead to the sinking of the boat. Therefore, a bilge pump is necessary.

 In some other cases, a severe leak caused due to a hole in the boat hull might require a powerful pump to drive out all the water from the craft. 

Bilge pumps will certainly buy you the time required for making alternative arrangements to repair the leak, return to the shore or leave the ship safely. Therefore, deciding to buy a bilge pump is going to be one of the wisest decisions taken.

This buying guide provides all the information about these products and a detailed explanation of the factors and essential features of the best boat bilge. Buyers should go through the article to arrive at the perfect choice of automatic bilge pumps. The Shoreline Marine Bilge pump is a popular 1100 GPH bilge pump. Buyers can also refer to the Shoreline Marine Bilge Pump for understanding the product in a better way.

 Why should you buy a Bilge Pump? 

There are a variety of bilge water pumps available in the market. With its multiple types and features, choosing the best bilge pumps can appear to be difficult. Numerous factors and features have to be considered while buying the best bilge pump. To begin with, the buyer should be aware of the benefits provided by the boat bilge water pump. This will provide enough clarity and help him or her to arrive at the right choice of the best automatic bilge pump.

 Bilge Pump Resists Flooding 

The bilge of the boat or the ship can be flooded with fluids from the drainage system, leakages and other sources washed down by waves. It is often a common occurrence when the overflooded bilge leads its way into the engine room of the ship. This can lead to huge problems.

Often the water that enters the bilge contains fuel or oil that might damage the machinery leading to rust and corrosion. Moreover, a flooded boat compartment would result in disruption of the entire boat balance.

The marine bilge pump prevents the flooding of the boat. Moreover, the effectiveness of a bilge pump can be understood in the case of recreational boats. The recreational units do not have deep bilge chambers leading to excess flooding chances affecting the electronics of the ship. An electric bilge pump comes with an automatic float switch. The internal float switch switches on the pump when the water rises above a specific level without having to constantly check the bilge.

 Delay Time in Sinking 

Apart from clearing the bilge well, bilge pumps can effectively delay the process of sinking. This means that if unfortunately, the craft receives a heavy blow resulting in a catastrophic leak or puncture, the bilge pump can drive the water out at a faster rate than the incoming water.

This will provide you the required time to repair the leak or make way for emergency docking. Therefore, it is always recommended to buy an automatic bilge pump that has a high gallon per minute capacity flow rate. Moreover, an automatic pump also helps to prolong the delay time in the sinking of the ship so that necessary arrangements can be made to abandon it.

 Free Space 

A bilge pump facilitates the optimum utilization of space. This means that the pump is small in size and can be used at the bottom of the boat without taking up much space.

 Price and Portability 

A bilge pump falls within an affordable price range. The buyer has to choose a pump that is suitable for his or her vessel. An automatic bilge pump is not too heavy on the pocket. Moreover, it can be carried from one place to another. This permits it to be stored in a different place when not being used and enhances the life expectancy of the water pump.

 Adherence to the Law 

A marine-grade bilge pump is not only necessary but also in adherence to the marine laws. This means that in case you have a large ship or a passenger ship, it is required by law to have a bilge pump installed inside your boat for emergencies. Moreover, it is also mandatory to have reliable pumps like the ones certified by ABS or DNV in compliance with international and national regulations.

 Bilge Pump Types 

For choosing the best bilge water pump, it is necessary to understand the different types of pumps and how they function at first. It should be remembered here that the bilge pumps can be primarily categorized as an electric bilge pump and a hand bilge pump. An electric bilge pump runs on power while a hand bilge pump has to be operated with a handle.

Here in this article, we are discussing the electric bilge pumps. These bilge pumps can be further categorized into two types. The first type is the automatic bilge pump, which comes with a float switch that switches on the pump once the water level rises to a certain altitude. The second type is the manual bilge pump, which has to be switched on manually. The SEAFLO Non-Automatic Bilge Pump is a 2000 GPH pump that comes with a stainless steel shaft and ignition protection feature.

Based on these two primary features the marine bilge pumps come in a variety of types that have been explained below. The buyer must go through all the types to understand and identify the type of pump that best suits his or her vessel.

 Centrifugal Pumps 

These are the most widely used bilge pumps. They are regarded as the best bilge pump for the greater capacities, ergonomic design, and the ability to withstand debris at an affordable price range. The buyers should understand that large vessels are typically implanted with centrifugal pumps because they have a better flow rate and can drive large quantities of water.

These pumps convert rotational energy into kinetic energy and discharge the water by making use of an impeller inside the pump. This lowers the pressure inside the pump and more water flows in it. These pumps have two essential operational units, the impeller, and the volute casting.

 The impeller is a disk that has vanes that have been curved on the exterior. 

The impeller is powered by a motor and it spins at great speed, which allows the vanes to make use of centrifugal force and push the incoming water to the sides of the casing. The volute casing gradually widens towards the outlet. This shape builds up the required pressure to jet the water out through the discharge.

As the water moves through the discharge, low pressure is created in the casing, which results in the pump pulling more water. The buyers should remember here that these pumps need to be primed beforehand for operation. Therefore, such a priming technique does not drive out all the water from the bilge.

There are two types of centrifugal pumps namely the automatic submersible bilge pump and the horizontal bilge pumps. The fully submersible bilge pump is meant for smaller boats. A submersible boat bilge has a waterproof casing and fits inside the bilge. On the other hand, horizontal bilge pumps are meant for larger ships and suck the water out of the bilge using pipes. The MAXZONE Automatic Boat Bilge Water Pump is an 1100 GPH stainless steel pump with a snap-lock strainer. The MAXZONE Automatic Bilge pump is a submersible unit and can be rated as one of the best pumps.

 Diaphragm Pumps 

This is another automatic bilge pump that is used widely. They are built on the mechanism of positive displacement. This means that a diaphragm pump is not meant for large ships. They do not have high pumping capacity and cannot withstand debris. These pumps are manufactured for small or medium-sized vessels. Moreover, these pumps do not require priming and can run completely dry.

These pumps can remove all the water from the bilge and can smoothly facilitate the pushing or pulling of water upwards. A diaphragm pump works with the help of a diaphragm and valves. The diaphragm creates a vacuum in the pump, which sucks the air or water through the inlet valve. Once the diaphragm goes down, the water is forced out of the outlet valve.

 One of the unique benefits of these pumps is that they come with a diaphragm, which can pull air too so the pump need not be placed near the bilge. 

There are three types of diaphragm pumps available in the market namely, single diaphragm pump, double diaphragms pump, and manual diaphragm pump.

Single pumps come with a single diaphragm that drives the water in and out. The double pumps have two diaphragms and lead to a more efficient pump system. On the other hand, the manual pump does not run on power. This manual bilge pump comes with a lever, which pulls open the diaphragm and has to be pushed to close it manually. This hand bilge pump can come in handy when the electrical system of the boat is down. The Bayite Diaphragm Pump seems like a perfect example of the product.

 Reciprocating Pumps 

The reciprocating pumps also follow the mechanism of positive displacement. They can run completely dry and can remove all the bilge water. They also facilitate the smooth pumping of water upwards. One of the features of reciprocating pumps is that they can work well with high viscosity liquids. This is the reason that larger ships make use of these pumps to remove the sludge from the bilge wells.

However, these pumps have a lower gallon per hour rate. This means that they cannot drive water as fast as centrifugal water pumps. Moreover, these pumps cannot withstand debris and the buyers must install a filter at the suction hose. They make use of a piston that creates a vacuum in the pump and pulls the air or water through the check valve. After the piston goes down, the water is driven out of the outlet valve.

 Flexible Impeller Pumps 

An impeller pump might look similar to a centrifugal water pump but they are completely different from one another. These impeller pumps make use of a rubber impeller that has been pressed by the casting to result in curvature. These pumps too follow the mechanism of positive displacement and enable self-priming.

Moreover, these pumps can remove all the water from the bilge well. These pumps can also withstand debris. However, the buyers should remember here that the flexible impeller pumps can never be run dry. This means that unlike its counterparts if this pump is run without water then the friction between the casing and the impeller will lead to the rubber impeller being burnt out.

The flexible impeller pumps make use of a rubber impeller to connect to a cam, which bends to drive the captured water out of the discharge. At the time the cam is left by the impeller, negative pressure is created that pulls more water out. This automatic bilge pump employs a simple design and comes within an affordable range.

 10 Best Automatic Bilge Pump – Everything You Need to Know 

Given the varied types and features of the automatic bilge pumps, the buyer might get overwhelmed while finding the right choice for his or her vessel. However, it is not every day that you buy an automatic bilge pump and you must strike a fair deal. Moreover, choosing the perfect product can result in a significant difference between sinking and saving the ship. One of the well-known brands with good bilge pump reviews is Johnson Pumps. The Johnson Pumps 32903 Cartridge Bilge Pumps is a perfect example of the product.

Furthermore, it is important to identify the best choice of the boat bilge pumps so that the buyer does not spend a fortune on the pump that does not cater to his vessel’s needs. There are some crucial factors and features like the GPM, boat size, and other pointers that will help you arrive at the perfect choice. This buying guide has compiled all the factors lucidly so that you can spot the best bilge pump easily.

 How to buy the Best Boat Bilge Pump? 

There is a range of factors that have to be considered while buying the best bilge pump. The buyers must go through these factors carefully to better understand their bilge need. The list of factors has been provided below.

 Type of Boat 

This is an essential feature that has to be analyzed before determining the right choice of a bilge pump. Buyers should remember that a small racing boat that rides on the rough sea and meets with a lot of action will need a better pump system than a large boat that operates on calm waters. Here for the convenience of the buyer different types of boats have been mentioned with their corresponding bilge pump.

• Daily sailing boats make use of a piston or a flexible impeller pump. They might also use a hand bilge pump.
• Ski Boats and Runabouts make use of an automatic submersible bilge pump that is installed in the lowest section of the bilge well. Boats that have stern drives might install the pump under the oil pan of the engine.
• Small boats meant for cruising and racing boats make use of a diaphragm bilge pump mounted in the cockpit.
• Offshore racing boats as per the legal regulations must have two manual pumps permanently installed at the cockpit and below it.
• Coastal or offshore boats make use of an electric bilge pump located in a boat compartment with a backup manual pump.

The above specifications can be summarized as the boats that venture on the rough seas must have a centrifugal pump. This is because these boats will require greater pump capacity that can be executed by the centrifugal bilge pumps. In case you need to thoroughly clean the bilge well then a diaphragm unit can be considered. The Amarine Made Pumps are popular in the market. The Amarine Made Submersible Boat Bilge Water Pump is a centrifugal submersible unit that comes with anti-airlock protection and can be regarded as one of the best pumps for heavy-duty vessels.

 Boats that move on calmer waters can consider having a centrifugal or a diaphragm bilge pump. 

An automatic submersible boat bilge might not be able to drive water up in case the discharge outlet is located above the bilge. However, such an automatic bilge pump is cheap, easy to maintain, and has a high GPH.

Diaphragm units are expensive but incorporate an easy installation process and can be easily repaired as they are not located inside the bilge. They also facilitate thorough cleaning of the bilge well as all the water is removed. Reciprocating pumps are not so much popular except in cases when dealing with sludge or high viscosity liquid. On the other hand, flexible impellers involve changing the impeller often due to damage.

 Gallons Per Hour (GPH) 

The marine bilge pump is primarily rated by the pumping capacity that is measured in units known as gallons per hour or gallons per minute. Gallons per hour of a pump indicates its performance. The higher the GPH the quicker will be the pump to drain the water out of the bilge. The buyers must be mindful of the fact that a heavy-duty pump has a higher GPH.

It is always wiser to buy a pump that has the highest GPH. This is because, in case of an emergency, the quicker the pump will be able to drive the water out of the bilge, the more time will the sailer have to repair the boat or make necessary arrangements. Therefore, a pump with a higher GPH can save the boat from sinking. The Attwood Sahara Automatic Bilge Pump seems like a perfect example of the product. The Attwood Sahara pump comes with a tinned copper wire.

Different ships have different GPM needs and there is no one general GPM that fits all. It is safest to go with the biggest bilge pump that you can afford so that it has the highest GPH. Buyers might as well think that smaller boats do not require bigger bilge pumps. However, smaller boats have smaller hulls that get filled in no time. Therefore, they require big pumps that can move the water out of the boat in no time. Having said that the buyer also has to consider the space available in the vessel for the pump and then make a suitable choice.

 Head of a Bilge Pump 

Apart from GPH, the other crucial factor that the buyer has to consider is the total head of the marine bilge pump. The centrifugal boat bilge pump does not smoothly drive the water upwards. Here the buyer must ensure that the pump can work with the length and height of the discharge outlet. This can be done by calculation of the total head and then comparing it with the head rating of the pump.

A simple formula for computing the total head can be:

Height + Fluid Pressure + Loss in Friction = Total Head

Here, in the above formula height refers to the measurement of vertical rise. It is measured in feet. This means that if the discharge outlet is 20 feet above the bilge pump then the height shall be 20 feet. Water pressure refers to the pressure exerted by the fluid in the pipe. The loss in friction refers to the loss in the flow rate due to friction. Several online calculators are also available to help you with this computation. Once you have the total head, get a bilge pump that is equal to or more than the total head.

 Calculate Your GPH 

The buyer should know this essential piece of information that the GPH metrics provided by the bilge pump manufacturers are measured in ideal conditions in which the water is near the pump and the discharge outlet is adjacent to it. A pump that has been rated by the manufacturers with a 10 GPM will move 10 gallons of water in one minute under such ideal conditions. However, in real life, the pumps move water at a much lesser speed due to several factors that are not present in the ideal condition.

This can be a significant issue for small boats that come with smaller hulls. This is because these boats might get flooded more quickly and banking upon a bilge pump that comes with a 10 GPM but drives water at a real rate of 3 GPM can be problematic. There might be other reasons for a low GPM rate. For instance, the GPM might fall due to voltage, head height, and loss due to friction.

The buyer should always remember that they should not completely depend on the GPH rate disclosed by the manufacturer. This is because if the buyer is not able to create the ideal conditions then only 30% of the manufactured GPM rating of the pump can be utilized. Therefore, it is wise to select the pump with the highest gallons per hour rate.

 Are you replacing an existing unit? 

In case you are replacing an existing unit, the new unit should have a compatible hose size and wire capacity. Moreover, the heavy-duty pump with the highest pumping capacity that matches the hose diameters should be chosen. Furthermore, if you are willing to spend some more dollars, then the pump capacity can be improved with an unchanged hose diameter.

 Manual or Electric Bilge Pump 

The heavy-duty centrifugal pumps give value for their money and are the easiest to install. However, these boat bilge pumps become ineffective when the electric system of the vessel fails. Moreover, this is likely to happen when a lot of water enters your boat. Therefore, it is often recommended to have an automatic pump along with a non-automatic bilge pump or a manual diaphragm bilge pump. The buyers can refer to the 1500 GPH Rule Bilge Pumps for understanding the product in a better way.

A non-automatic boat bilge pump comes with around 30 GPM on average. Handling a manual pump can be tiring, except for the high-end expensive models. The buyer must understand that one gallon of water can weigh around 8lb.

 Moreover, pumping it to a considerable height can be strenuous for the pump as well as the pumper. 

Furthermore, the location of the pump can add to the difficulty, in case the pump is located in a crawlspace. Therefore, it is crucial to install the pump in an accessible location. The buyer should be aware of the gallons per stroke and the ergonomics of the pump. This is to strike the perfect boat bilge pump combination. One of the best examples of a non-automatic pump is a Seasense Hand Bilge Pump. The Seasense Hand Bilge Pump has plastic housing and can be referred to by the buyers.

 Automatic Operation 

Automatic operation requires installing a bilge pump that comes with a float or an electronic float switch. The buyers must be aware of the fact that an automatic pump can move small amounts of water from the bilge. But it is not at all wise to depend on the automatic operation feature completely. You should have devices to verify whether there is a leak in the boat.

You can make physical checks on the boat by yourself. Moreover, a cycle counter can also be installed to record the number of times the automatic bilge pump turns on and off. So it can be studied for a better understanding of whether there is a puncture or not. Alternatively, you might also consider installing a light or a buzzer as a signal indicating the operation of the pump.

Another option includes buying a high-tech boat system that lets you modulate the bilge pump. It also comes with a feature of an alarm clock. It alerts the buyer of the water level inside the bilge well being high. This boat system also lets you control the engine, GPS, and other boat components.

 Number of Bilge Pump 

This is another crucial consideration that the buyer has to make before buying the best bilge pumps. The number of bilge pumps depends on the number of compartments that need to be connected to the pump. Every compartment of the ship that has moisture-tight seals requires a bilge pump. Or at least a pipe connection to the water pump located somewhere else. This means that each compartment inside the ship from which water flow is restricted should be connected to a bilge pump.

Heavy-duty ships comprise a vast network of piping systems, which gets connected to multiple bilge pumps. A strongly connected network of pipes running throughout the vessel leads to a proper drainage system. However, this can only happen in the case of large ships that can afford to have a well-connected piping system. In the case of smaller boats, it is recommended to have one or two bilge pumps in all watertight areas. The SEAFLO Electric Marine Bilge Pumps seem like a perfect example of the product.

 Location of Installation of a Bilge Pump 

The boat pumps should be installed at the lowest section of the boat. However, to avoid siphoning the discharge outlet should not be too much closer to the sea level. In the case of bigger ships going into the rough seas, there should be at least two bilge units at two different parts of the ship. This is because two different areas reduce the chances of both the bilge pumps being overflooded.

 Powering a Bilge Unit 

The power source used by the pumps installed in ships is the electric motors, the engine of the ship, or the emergency power generator. The buyers who are considering buying the best bilge pump should remember that an emergency bilge pump must have a separate power supply. In the case of smaller boats, it is recommended to go through the manufacturer’s product guide to operate the pump without any issue.

 Types of Pump Switches 

An automatic bilge pump can come with a variety of switches. The switches can be switched on manually, or be connected to a battery. The most prevalent type of switches has been listed down as follows.

 Built-in Float Switch 

Many pumps are available with a built-in float switch. This internal float switch comes is typically installed at the side of the pump. Such a construction simplifies the installation process especially in the case of vertical bilge pumps. Some pumps follow a unique mechanism of spinning the motors intermittently to find out whether water has been collected inside the bilge pump. However, it has a drawback of the motor operating even if there is no water present inside the bilge pump.

 Separate Float Switch 

A separate float switch helps in the conversion of a non-automatic bilge pump into automatic operation by establishing a connection between the pump and the separate float switch. These switches essentially come with a hinged float that leads to a completed circuit. It switches on the pump as the water level in the bilge pump rises. Previously, these switches used liquid mercury to facilitate the completion of the circuit. However, as liquid mercury is not environmentally safe, the mercury-free switch has replaced the former.

 Magnetic Float Switch 

Such a float switch system makes use of detector cells that get notified about the rising water level across the plastic housing by making use of an electronic controlled reed sensor system. This electronically controlled reed sensor system senses the water using an electrical field and has no moving parts. It does not get damaged due to wear and tear. They also prevent the pumping up of fuel onboard.

 Bilge Pump Pipes 

Every water-tight compartment inside the ship is connected to a network of pipes that is connected to a bilge pump system. The smaller crafts make use of hoses in place of pipes. The hose friction cannot be avoided but it can be lowered by using a smooth hose. A rough or coarse-textured hose will reduce the GPM of the pump. The buyer should remember that the hose size depends on the pump capacity and amp draw. They should refer to the product manual to understand the pipe or hose size and length.

 Discharge Process of a Bilge Pump 

A bilge pump collects the water from the bilge well and discharges it. However, in the case of ships that might involve the mixing of oil and other chemicals with water, the water has to undergo a filtration process. The bilge pump drives water into the bilge tanks that facilitate the separation of oil and water. The oil is driven inside the incinerator and the water is discharged overboard.

However, in case of an emergency, the filtration process is skipped to save time and lead to more and more pumping of water out of the bilge. The oil is not separated from the water and it is released overboard. This skipping is only allowed in times of emergency. It is required by law regulations to follow a strict environment-friendly practice.

 Bilge Pump Failures 

There are a few reasons due to which the bilge pumps might fail to operate properly. The buyer should be aware of these common happenings and should take proper measures against them.

• Restricted Flow – The diaphragm bilge pump moves water of similar volume at a constant rate. If due to some reason, the flow gets restricted, the pump keeps on trying harder till it fails. The motor of the pump does not burn but will make a halt in moving water.
• Siphoning – The phenomenon of siphoning can occur when a hose is connected to a water container above the beginning point. If there is a backward flow of water, it might lead to suction that will in turn lead to the drawing of water inside the boat. A discharge outlet above the waterline at a higher level on the hull can prevent the backflow of water. Moreover, a vented loop can also lead to the prevention of siphoning.
• Mud Boxes – The centrifugal bilge pumps can withstand debris. However, debris leads to increased pressure and slows down the flow rate. Moreover, the life expectancy rate of the pump also reduces. Therefore it is recommended to install mud boxes or strum boxes that filter out the debris from the pump.
• Faulty wiring – Exposure to saltwater, fuel, chemicals, and oil can damage the wiring. Therefore, it is recommended to make use of good quality tinned copper wire so that the wiring does not get affected.

These are the factors and features that have to be analyzed before buying the bilge water pump. Moreover, to enhance the life expectancy of the pump, there are essential steps that should be followed at regular intervals.

 These steps can be listed down as follows: 

• Bilge Clean – It is crucial to ensure that the bilge remains free of dirt and debris. It should be cleaned at regular intervals.
• Filter Clean – The mud box filter might be clogged with debris. It is important to check up on them and clean them regularly.
• Check the Float Switches – The automatic switches might malfunction or stop working. Therefore, the buyers must check up on the switches from time to time.

 FAQs 

 What are Non-Return Valves? 

A non-return valve comes with a bilge pipe system. These valves prevent siphoning by stopping the liquid from flowing back into the bilge.

 How often should the water pump be used? 

The pump must be switched on as soon as the water starts collecting inside the bilge well. The buyer should also implement systems that alert him or her about the pump automatically turning on and off.

 How to prevent siphoning a bilge pump? 

A discharge outlet above the water line at a higher level on the hull can prevent the backflow of water. Moreover, a vented loop can also lead to the prevention of siphoning.

 Conclusion 

These are the essential pointers that have to be kept in mind while buying the automatic boat bilge pumps. A bilge pump is an essential boat component and can be much useful in case of a leak. Or a puncture in the boat hull. Moreover, there have been numerous incidents in which a boat or a ship could be saved from a minor leak due to the bilge pump.

Buyers should understand here that a bilge pump cannot save the boat or ship against a strong blow. Or a severe puncture received due to the lashing of a big wave. This is because no bilge pump can come with enough GPM to compete with the flow rate of ocean water entering the hull. However, what the bilge pumps can do is prolong the hull filing time. In addition, it can buy the rider more time to repair the leak. This is why you should always go for the biggest pump with a higher GPH. Wishing you all the best. Happy Purchasing!