Most boats tend to use a system to remove water from their hull, and that system is called a bilge pump.
Most bilge pumps come on automatically, and many have the option to manually turn them on. No boat is a perfect seal, so to have bilge pumps to suck out the water is a good idea.
Since a jet ski is a type of boat, many wonder if they have some kind of system to remove water, too?
Let’s talk about that and how uncommon it is.
Does a jet ski have bilge pumps?
It’s common for most personal watercraft to NOT have bilge pumps. I say most, as a few will come with a bilge pump, but it’s not the norm.
Instead, a jet ski will have bailer tubes instead of bilge pumps.
Bailer tubes work similarly, it sucks extra water out of your jet ski’s bilge, but the difference is that bailer tubes only work when the engine is on.
Bilge pumps run off electricity and gets that power from the battery. So long as the battery in your boat is good, your bilge pump will suck out any extra water.
Bailer tubes work off the vacuum suction that is created by the jet pump to suck out any water in your bilge, let’s cover that next.
How Bailer Tubes Work
Bailer tubes are simpler than bilge pumps, it’s literally only tubes inside your jet ski.
The jet pump has one or two tubes that stick out and run into the bilge. These tubes curve upward and then back down, which helps prevent water from coming into the hull. They also use one-way check valves for extra protection.
When the engine is running, the impeller inside the jet pump spins and pushes water out through the nozzle. Just above the nozzle are the bailer tubes. As water rushes past these tubes, it creates suction that pulls any water out of the jet ski bilge.
When you turn the jet ski engine off, the impeller stops spinning, so no more water gets sucked out.
If your jet skis start taking on water, start moving right away and head for land. The suction from the jet pump is what keeps your bilge from filling up, it’s your only way to stay afloat.
Can you add a bilge pump?
You can add a bilge pump to a jet ski, and many manufacturers even sell OEM kits to make installation easier. There are also aftermarket and third-party options that work just as well—as long as your jet ski battery is charged.
Most bilge pump kits require drilling a hole in the fiberglass hull so the water can drain out. If drilling into the bilge makes you uncomfortable, it’s a good idea to let a jet ski dealership handle the installation.
OEM bilge pump kits often use an automatic float switch that turns the pump on when enough water builds up. Some kits are less ideal—they run constantly whenever the key is on, acting more like a second bailer system than a true bilge pump.
I’ve installed several Sea-Doo bilge pump kits myself. A bilge pump is not difficult, just a bit tedious. You’ll need to tap into the fuse box and drill into the side of the jet ski. If you’re comfortable with basic wiring and don’t mind taking your time, most people can DIY the bilge pump themselves.
The hardest part is mounting the pump to the bottom of the jet ski’s hull. Some bilge pumps need to be glued down with epoxy or attached using a special bracket. Some jet ski models have a built-in spot for an OEM bilge pump, but that only works with their brand. Third-party bilge pump options that move more water (higher GPH) and run automatically may need more planning, but they’re worth the effort if installed correctly.
Is a bilge pump needed?
Whether you need to have a bilge pump depends on how and where you ride your jet ski.
If you ride hard or in rough water, a bilge pump is a smart choice. Also, if your jet ski sits on a lift, and you don’t remove the drain plug, it’s a good idea to install an automatic bilge pump and keep the battery charged.
A bilge siphon system is not foolproof and not meant to be a solution that allows you to keep your jet ski in the water all the time. Their batteries are small and a pump running all the time will drain it, getting a solar charger can help, but still, it’s not perfect.
If you’re buying a new jet ski, consider making it a part of the deal. It’s better to get the jet ski dealership to install a bilge pump before you take delivery, as it’s one less thing to worry about.
Why Are They not Standard?
A bilge pump is not a standard on a jet ski because they’re more enclosed than boats.
Boats are like big open tubs, their decks drain directly into the bilge. So when a boat takes on water from waves or rain, it all ends up in the bottom of the bilge. That’s why boats need electric a bilge pump to remove the water and prevent sinking.
A jet ski is more of a closed system. While it’s not completely sealed, it’s much less open than a boat.
Jet ski manufacturers also don’t have the expectation of you leaving them in the water for long periods like you would with a boat. They assume you’ll store it on a trailer or a drive-up lift—just like it says in the jet ski owner’s manual.
However, that could change. Today’s jet ski are much larger than they were 20 years ago. With more space inside, it would make sense for manufacturers to start including a bilge pump as a standard feature.
It’s Not A perfect System!
Bilge pumps can help keep your jet ski from sinking if we will have a small leak, but they’re not a fix for everything.
A common myth is that they will guarantee you won’t sink. That’s not true. If there’s a big leak, the bilge pump might not keep up.
I’ve seen a jet ski with fist-sized holes in the hull, and even with bilge pumps running, they still sank. Add in the fact that a jet ski will have a small battery, and it’s clear these bilge pumps have limits.
That said, it’s still better to have one on your jet ski than not, it could make all the difference in an emergency.
Also, if anyone is wondering, a jet ski won’t completely sink. If you look in the bilge, you’ll see a bunch of foam. That foam has only one purpose, if the jet ski completely takes on water, that is what keeps it from sinking to the bottom of the lake or ocean. The foam is located at the nose and midsection, so if the jet ski sinks, the nose will float. But once on land, you’ll need to have a water pump or to pull the drain plug to get the water out.
As usual, another great, informative article. Thank you, Steven!