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Is it Normal for Water to Get Inside a Jet Ski? [Video]

Is it Normal for Water to Get Inside a Jet Ski? [Video]

Due to their design, jet skis tend to let a little water into their hull. Therefore, having a couple of cups of water in the bilge is normal after a ride. On the other hand, if an excessive amount of water accumulates in your ski, it’s a clue that it requires a thorough inspection.

Are you wondering where water gets into your ski and how to fix it?

Keep reading!

How does Water Get into a Jet Ski?

There are a lot of ways water can leak into a jet ski, but the most significant ways are the following:

  • Air vents
  • Drain plugs
  • Driveshaft bearing housing/carbon ring
  • Bailer system valve
  • Sponsons, intake grate, ride plate, and fittings
  • Trim and brake/reverse system
  • Exhaust and cooling system
  • Cracks in the hull
  • +1 During cleaning or storing
Let’s take a closer look at each!

Air Vents

Air vents on a jet ski are holes on the top deck designed to allow fresh air to flow into the hull. They are typically located high above water level around the seat, the neck of the handlebars, or on the front of the top deck.

Water can get inside the hull through these vents if you ride on choppy waters. Flipping the jet ski can also force water into the hull through the vents or, in the worst case, into the engine through the exhaust system.

(To avoid this, there’s a sticker on the stern of the ski that explains how to properly flip the jet ski.)

Drain Plugs

Leaving the drain plugs loose is another common reason for water accumulating in the hull of jet skis.

These plugs are intended to drain water out when the ski sits on the trailer. But since they are located under the waterline, they allow water to seep inside if they are not properly tightened.

What’s more, forgetting these screws can cause your ski to sink in a short time!Due to this risk, always double-check the drain plugs as part of the pre-ride check procedure.

Driveshaft Bearing Housing/Carbon Ring

Let’s move on and talk about some more serious malfunctions.

The driveshaft of jet skis connects the engine to the pump assembly.

To keep water out, the driveshaft utilizes a unique sealing system. On Yamaha and Kawasaki jet skis this device is known as the driveshaft bearing housing and it is bolted on the inside of the hull.

Although this assembly proves to be very durable, there is always a chance that the bolts can come loose or that the double lip sealing can crack.

If this happens, the bearing housing won’t be able to completely keep the water out.

Unlike this unit, Sea-Doo’s carbon ring seal is much less durable. This seal does the same job as the bearing housing on the competitor skis, but it’s prone to breaking or wearing unevenly.

Even with the slightest damage, it allows water to leak into the hull. So, if you have a Sea-Doo, it’s highly recommended that you keep an eye on the carbon ring seal.

Bailer System Valve

The bailer system is engineered to pull out bilge water using the jet pump’s suction. This bailer features a valve preventing the water from flowing backward.

A failure of this valve can also allow external water to enter the hull.

Sponsons, Ride Plate, Intake Grate, Fittings

The bolts of the various fittings and features under the waterline are also prone to getting loose.

These devices include the sponsors, ride plates, and intake grates, which can come loose over time. Another common issue is when these parts are incorrectly replaced after maintenance and water starts to leak through the screw holes.

To prevent these issues, it’s recommended to use some special waterproof silicone to seal these units. If your ski features a black hull, you can’t go wrong by using Permatex Ultra Black or Right Stuff.

Trim and Reverse System

Other potential leaking points on a jet ski are parts of the trim and the brake/reverse system.For example, Sea-Doo’s VTS system utilizes a rubber boot that is prone to leaking, allowing water to accumulate inside the VTS unit. This can damage the electronics and the motor of the VTS system.

Like the trim, the brake and reverse systems (like Sea-Doo’s iBR or Yamaha’s RiDE) also utilize push rods that go through the hull. A broken sealing around these units can also cause leaking issues.

Exhaust and Cooling System

Many jet skis utilize an open-loop cooling system that uses external water to keep their engines cool.

This cooling system routes external water from the pump to the water jacket to the engine through hoses. What’s more, the exhaust system and the intercooler (if featured) are also cooled by external water.

A cracked hose or a loosened connection in these systems can pump a significant amount of water into the hull. Therefore, they should be regularly inspected and maintained.

Although Sea-Doos are designed with closed-loop engine cooling, the exhaust and the intercooler of these machines are still cooled with an open-loop system.

What’s more, the exhaust system on the ski can also get damaged, resulting in water leaks.

Cracks and Damage on the Hull

Jet ski hulls are built of many different materials, but some tend to crack over time. Improper towing, a collision, or wave jumping can also damage the hull.


Water finds its way into the hull through these cracks.

Fortunately, most jet ski hulls can easily be repaired at a professional shop.

Cleaning and Storing

Interestingly, water can not only get into a jet ski during rides, many riders also notice some leftover water in the bilge after cleaning the engine and its compartment.

Sometimes you need to tilt the trailer up to allow the remaining water to flow into the bottom of the bilge. Note that it takes time for water to accumulate in the deepest point of the hull.

If you store your ski outside, it’s also recommended that you protect it with a high-quality cover. Leaving it uncovered can be harmful to your ski in many ways. For example, a bad storm can deliver water into the footwells or even inside the hull through the air vents.

Why is Your Jet Ski Full of Water?

If your jet ski is full of water after your rides, this is a clue that it has a problem and it needs to be inspected immediately. Just check all the parts listed above to ensure that everything works well and that the screw holes and robber boots are properly sealed.

Also, don’t forget that submerging and flipping the jet ski in water can deliver a significant amount of water to the hull. So, if you ride aggressively and frequently flip your ski, you may find a lot of water in the engine compartment.

How do You Find a Leak in Your Jet Ski?

How can I figure out where the water that’s getting into my ski is coming from? This is a common question of many riders, and the answer is surprisingly simple: pour some water into the hull and see where the water goes out.

Rinsing water into the engine compartment is part of the cleaning procedure anyway, as this is the only way to remove corrosive salt water from the engine.

All you need to do is put a garden hose into the hull when the machine is sitting on the trailer.

Then, slowly fill the hull with water but make sure that the water level doesn’t reach the battery, airbox/carburetor openings, supercharger, or other critical parts where water could flow into the engine.

If there’s some water in the hull, it should seep out where the leak is.

Conclusion – Is It Normal to Have Water in the Hull of a Jet Ski?

After each ride, do you find some water in your jet ski’s hull? If so, don’t worry!

Water leaks into jet skis’ hulls during rides regardless of their make and model. External water finds its way through the air vents next to the seat or through the front hood. Consequently, having a couple of cups of water inside your jet ski after a ride is completely normal.

On the other hand, too much water in the bilge is a clue to a malfunction. The critical parts where water can get inside the jet ski engine are as follows:

  • Air intakes
  • Drain plugs
  • Driveshaft bearing housing/carbon ring
  • Bailer system valve
  • Sponsons, intake grate, ride plate, and fittings
  • Trim/reverse system
  • Exhaust and cooling system
  • Cracks in the hull
  • +1 During cleaning or storing
Check these areas and systems carefully to keep excessive water away from your jet ski’s engine!