Most boats tend to use a system to remove water from its hull, and that system is bilge pumps.
Most bilge pumps come on automatically, with many having the option to manually turn one on. No boat is a perfect seal, so having a pump 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 pumps for bilge water removal system? Let’s talk about that and how it relates to Sea-Doo, Yamaha and Kawasaki watercraft.
Do jet skis have bilge pumps?
Most jet skis don’t come with one and instead use Venturi powered bailer tubes. I say most, as a few will come with a bilge pump, but it’s not the norm for jet skis.
Bailer tubes work similarly, it sucks extra bilge water out of your jet skis hull, but the difference is that bailer tubes only work when the engine is on.
Bilge pumps run off electricity and get that power from the jet skis battery. So long as the battery in your boat is good, your bilge pump will suck out any extra water.
Jet skis, on the other hand, use bailer tubes, and they work off the vacuum suction that is created by the jet pump to suck out any water in your hull. So the engine must be running in order for the bailer tubes to work.
This is why working on the jet pump can be tricky, if you don’t seal up the pump up right after working on it, the jet ski can take on water. Even worse, if not making a correct seal, the bailer tubes won’t work. That is why they use torque settings for the pump bolt install and a gasket that you must make sure is installed correctly.
How Bailer Tubes Work On a jet ski
Bailer tubes are simpler than a bilge pumping system, it’s literally only tubes.
The jet pump has one or two tubes sticking out that run into the hull. The tubes go up and then back down, so no water comes in, but they use a one-way check valve too.
Since they use the jet drive system, when the jet ski engine is on the impeller is moving, and that impeller moving drives water out the nozzle. Above the nozzle is the bailer tube(s), and water that rushes by creates a vacuum and sucks out any water in the jet ski hull through the bailer tubes.
When you shut the jet ski engine off, the impeller is not moving and thus no water will be sucked out.
If the jet ski taking on water, start moving and get to land, as the pump sucking out the water is the only thing keeping you afloat.
I had a few watercraft that started to take on water with me on it. One of the ways you can tell you’re taking on water is that the craft is easier to roll over or feels more tippy. I had one that rolled over way too easy and the key was so stretched out that it didn’t kill the engine, and I started to grab what I could to flip it and the engine was still running. If the engine is running, the impeller is spinning, and I started to grab the intake grate, which was super dangerous. This is why you need to replace your key or safety lanyard when they start to crack or become too stretched out.
Bilge Pumps Can Be Added
Bilge pumps can be added, in fact, many jet ski manufacturers even sell an OEM kit to make it easy. You can also buy after market or 3rd party bilge pumps that will work, so long as you got a charged battery.
Most bilge pump kits require you to drill a hole in your fiberglass hull, so the water can get out. If drilling a hull in the bilge makes you nervous, it’s best you let the jet ski dealership handle it for you.
The OEM bilge pump kits from the manufacturer don’t always use a manual switch and instead use a float switch that comes on when enough water is in the hull. Even worse, some kits run all the time when the key is on the watercraft, making it no more than a second bailer system.
I’ve installed a few kits for Sea-Doo before; It’s not hard, just annoying. You’ll need to tap into the fuse box and drill your holes in the side of the watercraft, but if you don’t mind messing with wires and going slow, it can be done by most people.
The tricky part about some jet ski bilge pumps is getting them to stick to the bottom of the hull, some you glue on with epoxy or get a special bracket. Some manufacturers will include a cut-out for it to make for an easy install, but it’s for their bilge pumps. The 3rd party ones that run automatically and push more water out (higher GPH) will need some extra thought, but it’s worth it if you can make it work.
Do You Need a Bilge Pump?
Having a bilge pump will depend on your riding style and where you ride your jet ski.
If you ride a jet ski hard or in rough water, some type of marine bilge pump system is a smart idea. If you never take out your drain plug while on a jet ski lift, it’s also a good idea to get an auto bilge pump system and keep the jet ski battery charged too.
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 dealership to install one before you take delivery, as it’s one less thing to worry about.
Why are bilge pumps not standard on PWCs?
The reason bilge pumps are not the standard on PWCs is that they’re not as open as boats.
Boats are giant tubs floating on the water, the deck of a boat drains into the bilge. So if you go over a large wave or caught in the rain, all that water dumps on the deck and then the bilge, so a electric pump to remove that water is needed or else you’ll sink.
A jet ski is more of a closed system, while not completely sealed it’s still not as open as boats.
Also, jet ski manufacturers don’t expect you to keep them in the water for weeks or months, like you would with a boat. They expect you to keep it on a trailer or drive-up lift, this is what they say in your owner’s manual.
If they keep making PWCs any bigger, this whole thing might change. The PWCs of today are so much bigger than the ones just 20 years ago. The more empty space inside the watercraft, the more bilge pumps make sense to be already geared up and ready from the factory.
Powered Bilge Pumps Can Stop PWCs from Sinking, To An Extent
These powered bilge pumps will keep your PWC from sinking from a small leak, but they can only help so much for large leaks.
A common misconception people get about electric bilge pumps system have been about how they will guarantee you won’t sink, this is not true and if the leak is big enough, they won’t help your jet ski much.
I’ve seen guys somehow put a fist size hole in their plastic/fiberglass hulls and the jet pump didn’t stop PWCs from sinking. Combine with the PWCs small battery, powered bilge pumps are not perfect.
But, overall, It’s better to get bilge pumps than not have one on your PWCs.
Also, if anyone is wondering, PWCs won’t completely sink. If you look in the hull, you’ll see a bunch of foam. That foam does only one purpose, if it 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 it sinks, the nose will float. But once on land, you’ll need a water pump or to pull the drain plug to get the water out.
As usual, another great, informative article. Thank you, Steven!