Sailboats & Bilge Pumps: 8 Answers (For Beginners)

As a beginner to boating or sailing, many new terminologies are to discover and boat systems to learn.

One of the systems on a sailboat that is very important to learn is the bilge pump and how it works.

Read on to discover all you need to know about sailboats and bilge pumps:

What Part Of A Sailboat Is The Bilge?

The bilge on any boat or ship, including a sailboat, is the inside, lowest part of the boat’s hull.

The bilge area of a boat or ship is designed to collect any leaks.

These leaks can come from excessive water on deck (which can include washing your boat or a lot of rain), holes or problems with the hull, fuel leaks, or any other accidental spills.

What Is A Bilge Pump?

A bilge pump is a waterproof pump that removes the collected water from a boat’s bilge and pumps it overboard.

They can be manual or electric and come in many different shapes and sizes. Bilge pumps are there to help prevent your boat from sinking, especially if it is left unattended or you develop a problem while out at sea.

However, if you have an accident and put a hole in your hull, a bilge pump alone will not stop your boat from sinking, but they are a last line of defense in case of small leaks and will help prevent flooding.

What Are The Different Types Of Bilge Pumps?

So, we have established a bilge pump, but is this a standard piece of equipment, or do they come in different types?

The following is a brief description of the 2 main different types of bilge pumps available for small, recreational boats:


Centrifugal pumps are submersible and non-self-priming, which means they must be sitting in the water to pump it out.

They usually remove most, if not all, of the water. The last drops you can then soak up with a sponge.

They work best when the bilge has a small integrated compartment where the water collects at a central point.


Diaphragm pumps are self-priming.

This means that they can pump water upwards through an intake hose and discharge it outside the hull.

They use a membrane to create a vacuum to draw water in and push water out. A diaphragm pump can usually remove all the water from your bilge and leave it fairly dry.

What Sailboats Have A Bilge Pump?

Every boat, whether sail or motorboat, will have some form of a bilge pump.

In fact, the Small Vessel Regulations in most countries require you to carry a manual bilge pump at the minimum. However, if your boat is less than 9 meters (29.5 feet) long, you may carry a bailing device instead of a pump.

While the US Coast Guards’ advice for recreational boating is that a manual bilge pump or bailing device is a highly recommended piece of equipment, different states, and indeed different countries, will have different laws with different requirements.

As a prudent boater, it is highly recommended to have one manual bilge pump on board.

It is not so important in shallow waters, such as on a river or lake, but you should never go out to sea without at least one functional bilge pump.

What Exactly Is The Function Of A Bilge Pump?

The main function of a bilge pump is to remove any water from the bilge of your boat.

During normal operation, a bilge pump can provide a convenient way to keep the bilge of your boat dry without having to roll up your sleeves and get out a bucket and sponge.

It can also buy you time in a potentially hazardous situation like a major storm where you have a lot of water coming off the deck or a leak caused by a failed through-hull fitting or from any hull damage due to a collision.

How Long Can A Bilge Pump Run Continuously?

Bilge pumps can be both manual or electric and come with different pump-out capabilities.

How long you can use a manual bilge pump will depend on how many spare hands you have and where the handle and pump are operated from. If it is in an awkward place, you will use your energy much faster than a place where you can sit or stand comfortably.

An electric pump should be fitted with an automatic float switch. This means that as soon as any water is detected in the bilge, theoretically, the float switch should activate the electric bilge pump to switch on and switch off as soon as the water has been removed.

These days, most pumps are electrically powered, but most boat builders still fit manual pumps. If we compare the two, and if power is available, electric pumps are unlimited in their pumping capacity and are faster than manual pumps.

However, manual pumps have the advantage of their ability to be used, even when you are out of battery power.

Does My Sailboat Need A Bilge Pump?

A bilge pump should be considered an essential piece of equipment for your sailboat.

Although small boats, or boats under 15 feet in length, don’t need to be equipped with an electric bilge pump because you can manage with a manual pump or even a bucket and a sponge.

However, you need a bilge pump for bigger boats because you don’t know when water or other liquids may get into your boat’s bilge. When water gets in, you need to get rid of that water. Supposing a seacock fails or you hit something which puts a hole in your boat?

Whatever the source of water coming into the boat, you may not be able to pump it manually. So, it would be best if you had an electric bilge pump for larger boats.

In addition, if your sailboat is too big to fit on a trailer, and is kept in a marina or on a mooring, what happens when you’re not there?

A bilge pump combined with a float switch will activate if there is water in your boat, even if you are not on board.

What Are The Best Brands Of Bilge Pumps?

While there are many different brands of bilge pumps available, the following brands are the ones that regularly feature in the Top 10 lists:

Rule –

Rule manufactures a range of bilge pumps with different water pump-out rates per hour.

The rule is a brand that has been around for a long time and has become a standard that many boaters use as a measure against other brands.


Seaflo offers a choice of bilge pumps that are automatic, non-automatic, and manual.

Their flow rates range from 500 to 2,000 gallons per hour (GPH). They also offer various accessories, including float switches, through-hull fittings, deck wash down kits, and much more.


Attwood makes a complete selection of bilge pumps suitable for small runabouts, cruisers, yachts, and even commercial boats.

Attwood bilge pumps are tested and approved as standard equipment by many leading boat manufacturers.


Maxzone is another brand that regularly pops up in the Top 10 Bilge Pump lists.

They have a range of automatic and non-automatic submersible bilge pumps designed to clear water in any sized boat.


Shoreline offers the best value for money option on the market.

They offer a selection of bilge pumps and accessories, which all have marine-grade wiring.

This means that not only are the pumps safe to install, but they are also easy to set up by the DIY boater.

Final Thoughts

After taking possession of your ‘new’ boat, you should always make sure that you familiarise yourself with all of your boat’s safety gear, including the bilge pump operation and any manual handles.

Often the manual bilge pump handles on second-hand boats are in far-flung places, are not easily accessible, or are the wrong size.

Knowing how to operate your bilge pump system correctly could be the difference between your boat sinking or staying afloat.


A Boater’s Guide To The Federal Requirements For Recreational Boats¬†

Best Bilge Pumps –

How To Select A Bilge Pump

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