The 10 Best Bilge Pumps
Editor's Notes
June 20, 2020:
In an ideal world, we could determine the quality of a pump based purely on a combination of its price as well as its running costs, and the best pumps would be the ones with the lowest cost-to-GPH ratios. However, not all pumps are built equal, and durability and reliability are massive factors, particularly when you're out at sea.
The updates I've made reflect all of these factors, and I've swapped out older, less reliable and more expensive pumps, for options that offer better value. For instance, while the Attwood Sahara had a low power draw, it was quite expensive to buy, and had a few reliability issues, so I've replaced it with the Eco-Worthy 1100GPH - a pump that offers the same capacity, but is quite a bit cheaper and more reliable, and very quiet too, even though it has a slightly higher power draw.
On a similar note, I've replaced the Amarine-made 760GPH with the Sail Flo 750GPH. Again, the former was struggling with a few reliability issues, particularly related to the automatic switch that is turned on by the sensor. The replacement uses a very similar design and switching mechanism as most automatic pumps do, but it's more reliable.
All of the other pumps were fine in terms of capacity and reliability. Seaflo makes some sturdy models, and we've listed both the Seaflo 750GPH and Seaflo 2000.
Bilge pumps are versatile, and many owners utilize their pumps at home as sump pumps and pool pumps when they aren't being used on their boats. However, sump pumps are a lot more powerful as they're designed to run on AC voltage, while bilge pumps are made for boats and are thus made to run on DC batteries for portability. As such, bilge pumps can make good backup sump pumps for when the power goes out.
I'm in favor of technology making my life easier, and I would always recommend an automatic bilge pump over a hand-pump as one of your primary options. However, because automatic pumps run on batteries, it's always a good idea to have a hand-pump as a manual backup on the high seas. Thus, I've left in the current handheld models - the Seattle Sports Paddlers and SeaSense Hand Pump - but I've moved them towards the back of the list.
How Important Is A Bilge Pump Really?
They think their boats will never flood, so they tend to ignore bilge pump maintenance or make due with an inadequate system.
With all of the time and energy spent maintaining the engine and electrical systems, ensuring the Bimini top opens and closes smoothly, keeping the bottom clean, checking riggings and dock lines for wear, and various other tasks, it is no wonder that some things tend to fall by the wayside. While all of these things are important, there is one vital area many boaters seem to ignore — bilge pumps. For some strange reason, many people just don't think they are all that important.
Why the common lack of concern? Well, most people just don't seem to think anything is ever going to happen to their hulls. They think their boats will never flood, so they tend to ignore bilge pump maintenance or make due with an inadequate system. It is usually only the people who have had a boat sink or a hull flood (a more common occurrence than one might think) that take them seriously.
The truth is though, bad things happen. If they didn't, the government wouldn't mandate you have one life jacket aboard for every passenger. According to BoatUS, a marine insurance company, aside from hurricanes, sinking is the most common and costliest source of claims. And it usually isn't from ramming a huge underwater object or colliding with another boat. Two-thirds of recreational boat sinkings actually happen on a mooring or at a dock. This is because over 33 percent of boats sink due to the failure of a fixture or small part below the waterline that the owner didn't properly maintain.
Even with the staggering number of boats that sink at the dock or on a mooring, that should be the least of your worries. Things really become catastrophic when you are out on the open sea and something goes wrong. Maybe your exhaust hose fails and the engine starts pumping water into your hull. Maybe corrosion causes a sea cock to fail. It is in these moments when a proper bilge pump system can be a life saver. It will be able to keep your boat afloat long enough for you to find the leak and fix it, or get yourself safely back to a dock.
Selecting The Right Bilge Pump System For Your Boat
It isn't as easy as it might seem to pick the right size and number of bilge pumps for a boat. This is because there is no one size fits all answer. We can't just say that any 20- to 25-foot boat needs a so and so gallon-per-hour pump. Many different factors come into play when determining what is the correct bilge pumping system for a particular vessel, including boat size, design, and propulsion system. Certain types of boats are more vulnerable to sinking than others.
Let's start with a basic minimum pump number and capacity for some common boat sizes and then work our way out from there.
Let's start with a basic minimum pump number and capacity for some common boat sizes and then work our way out from there. For a 16- to 20-foot boat, the minimum adequate system would be two pumps with a 2,500 GPH capacity. A 21- to 26-foot boat requires at least two pumps with a 3,000 to 3,500 GPH capacity, and a 27- to 35-foot boat at least three pumps with a 3,500 to 4,500 GPH capacity. One should note that most pumps only actually move a fraction of their rated capacity, so it is worth buying a more powerful model than you think you need.
Now, let's look at factors that will affect how many pumps an individual boat needs and what capacity. One should start by evaluating their hull design. How many separate watertight compartments or hull dividers does your boat have? Every compartment that doesn't allow for the free flow of water to the other compartments needs its own bilge pump.
The next step is to determine how many total pumps you need in each location. In addition to having one in every watertight hull compartment, it is important to have a redundancy pump where water accumulates in your boat. For some, the water will settle at a different location when underway than when it is at rest. On stern drive boats and those with outboard motors, the back of the boat is usually lower in the water than any other part of the hull when at rest and underway, so they would only need a redundancy pump in the aft section. For those with inboard motors, the center bilge area is often lower when at rest, but the aft is when underway. These would need a redundancy pump in both of these locations. On sailboats, the water tends to always accumulate in the keel sump, so they would only need a single redundancy pump and in that location.
Maintaining A Bilge Pump System
There is no point in installing a adequate bilge pump system in your boat if you aren't going to bother maintaining it. After all, how useful will it be if it fails right when you need it most? Luckily, maintaining a bilge pumping system is easy. You should periodically check every one of your pumps by turning them on manually to make sure they are working. It is also important to regularly clean the strainers on your pumps to prevent them from getting clogged. At the same time you clean the strainers, take the base off the pump and clean the interior.
It is also a good idea to replace them at least every couple of years.
It is just as important to keep your boat hull clear of debris as it is to keep the strainers. Even if something isn't actively clogging your pump now, it may if water gets into your hull and it winds up floating against the pump strainer partially blocking the water flow.
One of the major failure points in a bilge system is the float switch. While they are fantastic devices that allow your pump to turn on automatically if the water level reaches a certain point, they are notoriously prone to failure so it is important to check them often. Make sure nothing is blocking them from floating up with the water level. It is also a good idea to replace them at least every couple of years. They are cheap and the process only takes a few minutes.