Do Jet Skis Have Reverse? How Does It Work?

Most modern jet skis have a reverse feature that allows them to move backward. The impeller cannot reverse direction. Rather, there is a wide curved deflector (the bucket) that covers the jet nozzle and redirects water underneath the jet ski, causing to move backwards.

This same bucket is also used as the “brakes” for a jet ski. When in neutral or with engine off, the bucket covers the nozzle as well. But when reverse is applied on the controls, it moves deeper under the nozzle to redirect water flow.

Contrary to what other sites or common sense might tell you, jet skis cannot reverse the direction of their impeller. In order to properly operate a jet ski, it’s important to know all of their features. One of the most useful features is the reverse function. I use it for docking regularly.

Riders should become familiar with operation of these functions to become safer and better riders. Let’s look at how a jet ski works and how a personal watercraft achieves its neutral and reverse features.

Sea Doo Spark IBR demonstration

How does a jet ski work?

For the most part, a jet ski, also commonly known as a PWC (Personal Water Craft), has an engine based similar to that of any motorized vehicle. That means that it has a piston-cylinder based engine that is placed underneath the seat of the jet ski. Modern skis use standard 4-stroke motors while some older skis are powered by 2-stroke engines.

When the jet ski is running, the torque from the engine is thrust directly onto a drive shaft that has an impeller attached towards the end of it.  As the engine runs, the driveshaft is always rotating, and so does the impeller. The shaft and impeller on PWC’s rotates only in one direction at all times (except for the newly introduced flushing system used to clear debris available on a limited number of Sea Doo models.)

How does the jet ski move forward?

Jet skis have water intakes positioned at the bottom or sides that allows the turning impeller to pull in water. No matter what design a jet ski has, the movement principle is the same. As the impeller starts to rotate, it sucks water through the bottom that is pushed through a tube and out of the rear of the ski to propel it forward.

This strong intake of water is the main reason you shouldn’t run a jet ski in shallow water, since you could suck in debris and damage the pump or impeller.

The throttle controls the speed of impeller rotation which controls water flow, and thus determines the speed of travel of the jet ski. Due to the fact that the force is pushing the water out the back end of the jet ski, the resulting opposite force pushes the jet ski in a forward direction.

The type of engine that a jet ski has is thus known as a direct drive system because of the fact that the engine is connected directly to the impeller. 

The water used to drive the ski is also used to cool the motor, impeller shaft, exhaust and other moving parts, at least in part. The engine’s heat is dissipated by the water flowing through the impeller tube, and the engine does not overheat. 

Sea Doos also have a separate closed loop cooling system that uses standard coolant like a car.

Yamaha’s RIDE system demonstration

Does a jet ski have a transmission?

Although the principle of a jet ski’s engine works very similar to that of any motor vehicle, the one difference is that a jet ski does not have a transmission and thus does not have gears. This again is due to its direct drive nature.

Does a jet ski have a reverse gear?

Although a jet ski does not have a transmission that changes speed and direction of the impeller and shaft, it can still reverse or be placed in neutral.

Sea Doo rear bucket movement shown out of the water

How does a jet ski reverse work?

Situated at the back of the jet ski is what is called a steering nozzle. This nozzle directs the flow of water in a certain direction which is controlled by the handlebars. Therefore if you move the handlebars, the nozzle will direct the flow of water in that same direction to move the jet ski left or right. 

The steering nozzle also controls the forward, neutral, and reverse of the jet ski. The jet ski is propelled forward because of the direct-drive system ( the water is forced past the impeller out the back, pushing the jet ski forward). Due to the fact that this is the only force by which the jet ski can move, the steering nozzle has has to redirect the water jet output to allow for neutral or reverse.

When the jet ski is placed in neutral, the steering nozzle will cover the thrust nozzle and will not allow the water to be forced out in any direction. Therefore the jet ski will stay in place even when it is on, and the motor is running. 

When a jet ski is running at idle speed, there is still some rotation of the impeller and shaft. So it cannot maintain its position unless the jet flow is controlled. Even though the flow is slow, it is still always there. Partially covering the output allows the ski to effectively be placed in neutral to keep positions steady.

Riders will need to be aware of a slight drift in motion that can occur while in neutral. When combined with wind and current, your ski may move around a little while in neutral. Be cautious of this around riders who have fallen off, docks, shore, other watercraft, etc.

When the jet ski is placed in reverse, the curved steering nozzle plate will fully cover the thrust nozzle, and it will actually be positioned in such a way that the water will be directed towards the bottom and front of the jet ski. This means that because the water is being thrust in a direction that is in a forward direction, the jet ski will move in a backward direction (reverse). 

If this concept of the thrust nozzle is a bit difficult to grasp, take a look at the videos throughout this post which will demonstrate how each brand works.  

Kawasaki was last to market with a reverse option, and it is less elegant than the others

Do all jet skis have reverse?

For the most part, most modern designed jet skis now come with reverse. However, It is important to note that older models and some models designed to be “stand up” jet skis do not come with reverse. 

Why do jet skis have reverse?

When jet skis were first designed, the features of reverse were not included, and what you would need to do is turn around if you needed to go back to a particular location. 

The “reverse gear” was introduced because of various safety reasons and for practicality. The first is that water hobbies and especially jet skis have become very popular and most individuals who ride a jet ski are novices and hence need more safety features. 

A lot of new jet ski owners aren’t aware that there is constant impeller rotation and jet flow even at idle speeds. So many new owners found themselves striking other boats or docks when they thought their ski was stopped. Boats do stop rotation of their propellers when the throttle is closed, so this characteristic of jet skis isn’t intuitive to new owners who may be used to boat operation.

Another reason for the reverse feature is that it is much easier to get the jet ski back into position when trying to dock it safely. Using neutral and reverse judiciously around docks makes them very controllable at slow speeds, and prevents unwanted scratches, scuffs and dents. It also makes you look like a pro once you’ve mastered the art of docking without having to grab onto part of the dock or another boat to stop.

The Sea Doo Intelligent Brake and Reverse (IBR) System

Conclusion

To summarize, jet skis technically do not have a reverse gear because a gearbox is a part of a transmission system that a jet ski does not have. Remember a jet ski is based on a direct drive system that always rotates in one direction and always pushes water through the rear output, even at idle.

However, a jet ski has a neutral and reverse feature that allows it to stay in place or move backward because of the direction of the impeller’s water which is positioned by the steering nozzle. 

The last thing to note is that most modern jet skis do have this feature, but some older models may not.