Bilge Pump Guide

Automatic vs. Non-Automatic Bilge Pumps

Which One Is Right for Your Boat?

Bilge pumps are essential safety equipment on any vessel, from small fishing boats to large yachts. Understanding the difference between automatic and non-automatic bilge pumps—and how brands like Rule, Attwood, Johnson Pump, and Whale compare—can help you make the right choice for your boat.

What Is a Bilge Pump?

A bilge pump removes excess water from a boat’s bilge, keeping your vessel dry and safe. There are two main types:

• Automatic Bilge Pumps: Turn on automatically when water is detected.
• Non-Automatic Bilge Pumps: Require manual activation via a switch.

Automatic Bilge Pumps

An automatic bilge pump is a vital piece of equipment designed to help keep your boat dry and safe by removing excess water from the bilge — the lowest part inside the hull where water naturally collects. These pumps are typically installed with a built-in float switch or paired with an external switch that activates the pump when water levels rise beyond a certain point. As the name suggests, an automatic bilge pump operates without the need for manual activation, giving boaters peace of mind whether they’re onboard or away from their vessel.

The primary purpose of an automatic bilge pump is to prevent flooding and protect critical components from water damage. Rainwater, rough seas, hull leaks, or even splashes from waves can all introduce water into the bilge area. Left unchecked, this water can compromise your boat’s buoyancy and damage electrical systems, fuel tanks, and engine parts. An automatic pump provides round-the-clock protection by kicking on whenever necessary—keeping your boat safer, dryer, and ready to go at a moment’s notice. For any boat owner, especially those with moored vessels or who venture into unpredictable waters, having an automatic bilge pump isn’t just convenient—it’s essential.

Non-Automatic Bilge Pumps

A non-automatic bilge pump is a manually operated pump that requires the user to either flip a switch or activate it directly to remove water from the bilge area. Unlike automatic models, these pumps do not turn on by themselves when water levels rise. Instead, they are controlled by the boat owner or crew, offering a more hands-on approach to bilge water management. Non-automatic bilge pumps come in both electric and manual varieties, and are often simpler in design, making them more affordable and easier to maintain.

Choosing a non-automatic bilge pump can make sense for smaller boats, day cruisers, or vessels where the risk of significant water intrusion is low and the operator is usually onboard. Some boaters prefer the reliability and control that comes with a non-automatic system, as there's less risk of pump failure from a faulty float switch or battery drain from constant standby mode. These pumps are also a great choice as a backup to an automatic system, providing an extra layer of security when needed. For budget-conscious boaters or those who like to keep things simple, a non-automatic bilge pump remains a solid, dependable option.

Which One Should You Choose?

Choosing between an automatic and non-automatic bilge pump depends on your boating style, vessel size, and how often you're aboard. An automatic bilge pump is ideal for boaters who leave their boats moored or unattended for periods of time—it kicks on by itself when water levels rise, offering constant protection from unexpected leaks, rainwater, or wave splashes. It's a worry-free solution that can help prevent costly damage. On the other hand, a non-automatic bilge pump gives you full manual control, making it a great option for smaller boats, day-trippers, or anyone who prefers a simpler, budget-friendly setup. Some boaters also use non-automatic pumps as a backup system in case the automatic one fails. Ultimately, it's about balancing convenience, peace of mind, and how hands-on you want to be with your bilge management.

Installing a Float Switch

If you have a non-automatic bilge pump, adding a float switch is a smart upgrade that can convert it into an automatic system—giving you the best of both worlds: manual control when you want it, and automatic protection when you're away. There are two main types of float switches you can pair with a non-automatic pump. The first is a mechanical float switch, which uses a buoyant arm to rise with water and trigger the pump via a physical switch. These are affordable, easy to install, and work well in most clean bilge conditions. The second option is an electronic float switch, which relies on sensors rather than moving parts, making it ideal for dirty or debris-filled bilges where mechanical switches might get stuck. Adding either type of float switch increases your boat’s safety and convenience by ensuring that water is removed automatically—especially helpful during heavy rain or when your boat is docked and unattended.