I’ve been in the jet boat industry for years, and when I Googled “are jet boats reliable,” I was shocked at what I saw.
There is a lot of lousy information, especially from people who never owned a jet boat.
The answer to this question is simple, YES! One could even argue a jet boat is more reliable than other boats.
Why Jet Boats Are More Reliable
What is reliability?
Something that doesn’t break down all the time and keeps going. The less moving parts you have, the less something can go wrong, and thus the more reliable it is.
That is what describes a jet boat.
A jet boat has fewer moving parts than any other boat, especially stern drives.
As talked about in our post about jet boats having reverse, we learned that jet boats don’t have a transmission.
If you have no transmission, you have fewer things to break and fewer things to fix. A regular boat needs to shift into and out of gears. This requires a complex system and maintenance to keep it going.
A jet boat uses a simple reverse bucket that redirects the flow of water. It could not get any simpler than that.
Why Jet Boat Engines Are Reliable
The more common jet boats are from Yamaha, Scarab, and Sea-Doo. All 3 of these manufacturers use a jet ski engine.
I know many “boat experts” will scoff at the idea of a boat having a jet ski engine, but let’s break this down.
The most common engine block in a lot of boats is some form of the Chevy Big Block. Yes, the same engine you’ll find in an SUV is what powers a lot of boats.
Jet Boat Engines are Built For The Water
Would it not make more sense to have an engine that is built for the water? The engine in your car is built for the stop and go traffic on your commute to work. A boat is meant to be kept at one speed all the time. The abuse a car goes through is very different than a boat, so why are they using the same powerplant?
To give you an example, Sea-Doo and Scarab both use the Rotax purpose-built jet ski engine. This engine was designed to be used on water, and you can tell.
To cut down on space and increase reliability, the Rotax marine engine only has three cylinders. A car engine used in boats will have six but more commonly eight cylinders. That is 5x more things to break and maintain. That is five more sparkplugs to change and five more times for the engine to fail a compression test.
Not only that, but the Chevy Big Block in boats use belts and pullies like your car. Just like your car, these belts need to be replaced and checked.
A jet ski engine is entirely self-contained, and they use more reliable internal chains too. With saltwater, sand, and water a boat engine will come in contact with it only makes sense to have a self-contained engine.
Jet Boat Cooling System Keeps Things Going For Longer
Sea-Doo doesn’t make jet boats anymore, but Scarab Jet Boats has taken over and used their bodies and engines.
The great thing about Scarab Jet Boats is that they use the closed-loop cooling system that Sea-Doo uses in every one of their PWCs.
This is often a feature reserved for more expensive boats or an extra charge for your stern drive boats.
A closed-loop cooling system is huge when riding in the coastal and saltwater areas. This is because a closed-loop cooling system doesn’t take in any water to cool the engine.
A massive perk of closed-loop cooling is that it can keep the temp more even for the engine and extend it’s run life.
Since the Sea-Doo Rotax engine is built for the water, it’s got the coolant pump built-in and no extra crap to worry about like belts. A regular boat will need that additional pump that is connected to belts that also need to be replaced just like your car.
Another interesting fact about jet boats when it comes to cooling the engine or exhaust is the jet pump itself. The jet pump is a water pump, no duh, that is what moves you forward. Not only that, but it also acts as a coolant pump too.
The jet pump has a small hole in the housing where water is pushed through when the impeller spins. This water goes to the cooling systems of jet boats that don’t have closed-loop cooling like Yamaha Jet Boats.
A regular boat has a water pump too, but it’s not from the impeller. This means another thing to maintain and watch out for. Not only that, but this water pump is fragile and needs water on it all the time – this is why when you run a regular boat out of the water, you need the hose running all the time with a specialized attachment. Just more stuff to worry about in comparison to a jet boat.
Jet Boat Steering Is Super Simple
Another thing a regular stern drive boat have in common with cars besides the engine itself is the steering. Both use hydraulics to move the things that steer you. A car moves the wheels, and a boat moves the propeller left and right.
You need that hydraulic system because both are hard to move without it. But this means maintenance on the steering system and something else that needs to be connected to the engine: the more moving parts, the more things to go wrong.
A Jet Boat Steering Is Simpler Than Others
In a jet boat, you’re only moving the nozzle that is connected to the jet pump. The nozzle moves left and right, which gives your jet boat direction.
This nozzle weighs about as much as a laptop, if not lighter. It’s also not hard to move either, even with water rushing out of it. In fact, you could move the steering wheel of a jet boat with just your pinky finger if you wanted to at any speed – though I recommend keeping your hands on the wheel.
It’s just a simple steering cable and some hinges that control the steering on a jet boat. There is no complicated hydraulics system, pumps, actuators, and so on to worry about like you would with a regular boat.
Drive Protections = More Time On The Water
When it comes to reliability, we can’t forget the drive protections.
A regular boat will have the propeller fully exposed. Not only is this a safety concern but also something to get caught on rocks or get ropes tangled.
I’m not going to say a jet boat won’t get ropes or rocks sucked up because they can. What I am saying is how they handle these events is different.
One example is Scarab Jet Boats with the protective sleeve over the driveshaft. In the event you do suck something up that protective sleeve makes it less of a problem. Also, Yamaha Jet Boats have a cleanout port to make it easy to clean out the driveshaft too.
A Regular Boat Has Nothing
If you get rope wrapped around the propeller, you’re stuck until you clean it out. Nothing is protecting it.
The outdrive or propeller of a regular boat also hangs lower than the actual boat. A jet boat has nothing hanging lower; everything is inside the jet boat.
When you have something hanging lower than the boat, you need to pay more attention to shallow areas. Your outdrive hitting a rock can be costly, but a jet boat has nothing hanging below the boat, so nothing to worry about.
Once again, I’m not saying jet boats are perfect. They do have their problems with sucking things up because it is, after all, a super-powerful vacuum. But if you ask me running into shallow areas and having no protections in place is a more significant concern.
One more example is the wear ring on many jet boats. The name is confusing because it’s not a wear and tear item like tires you need to replace often. A wear ring is for protecting the pump from damage. In the chance you suck something up, the wear ring takes most of the damage and is easier and cheaper to repair.
When it comes to reliability, it’s not always about stuff not breaking but also about what happens when things do break.
If the worst thing to happen to a jet boat is damaging a wear ring, I’ll take that over destroying an entire outdrive of a regular boat because you didn’t notice that shoal marker.
Jet Boats Don’t Have Trim – Keeping It Simple
It’s rare to find a jet boat with trim beyond the WAKE versions.
A jet boat doesn’t need a trim as it doesn’t have the bow rise that other boats have. If you don’t have trim then it means one less thing to worry about and one less thing to break.
It also means it’s easier to drive a jet boat because you have less to mess with too.
Jet Boats Are Better
I simply don’t understand how anyone can say a jet boat is less reliable than stern drive boats.
- A jet boat has fewer moving parts.
- Simpler engines that are built for the water.
- Better cooling systems that are more robust.
- Less complicated steering system.
- Protective systems for the drive.
- No trim to worry about.
To get any simpler than a jet boat would mean buying a paddleboat. A jet boat is a more reliable option for the simple fact it has fewer things to go wrong when you compare it to other “normal boats.”