What Size Boat Requires a Bilge Pump?

Boats are a great way to explore the water and enjoy the outdoors. However, owning a boat also comes with the responsibility of maintaining it properly. One essential component of this maintenance is the bilge pump.

The bilge pump helps keep water from accumulating in the bottom of your boat, preventing it from sinking. But what size boat requires a bilge pump? In this article, we will explore the answer to this question and provide some helpful tips for choosing the right bilge pump for your boat.

What is a Bilge Pump?

Before we dive into determining what size boat requires a bilge pump, let’s first understand what a bilge pump is and how it works. A bilge pump is an electric or manual device used to remove excess water that accumulates in the bottom of boats.

This excess water can come from rain, waves, or leaks in the hull. The purpose of a bilge pump is to prevent water from causing damage to your boat or causing it to sink.

What Size Boat Requires a Bilge Pump?

The size of your boat determines what size bilge pump you need. A general rule of thumb is that you need one gallon per minute (GPM) of pumping capacity for every 10 feet of your boat’s length. For example, if you have a 20-foot boat, you’ll need a bilge pump with at least a 2 GPM capacity.

However, it’s important to note that this rule only applies to boats without air conditioning or other systems that require through-hull fittings below the waterline. If your boat has these systems, you’ll need to factor in their requirements when choosing a bilge pump.

Types of Bilge Pumps

There are two main types of bilge pumps: submersible and non-submersible.

Submersible pumps are designed to be placed directly in the bilge, where they can pump out water as it accumulates. These pumps are typically more efficient and effective than non-submersible pumps.

Non-submersible pumps, on the other hand, are installed above the waterline and use hoses to pump water out of the bilge. These pumps are less expensive than submersible pumps but may not be as efficient.

Choosing the Right Bilge Pump

When choosing a bilge pump for your boat, it’s important to consider not only the size of your boat but also its intended use. Boats used in rough waters or for extended periods may require a more powerful bilge pump than boats used in calm waters or for shorter trips.

You’ll also want to consider whether you want a manual or automatic bilge pump. Manual pumps require you to physically activate them when you notice water accumulating in the bilge. Automatic pumps, on the other hand, will turn on automatically when they detect water in the bilge.


In conclusion, what size boat requires a bilge pump depends on the size of your boat and its intended use. A general rule of thumb is one gallon per minute of pumping capacity for every 10 feet of your boat’s length.

It’s important to choose a bilge pump that meets your specific needs and consider factors such as submersible vs. non-submersible and manual vs. automatic operation. With proper maintenance and upkeep, a bilge pump can help keep your boat safe and dry for years to come.

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Daniel Bennet