Can a Sea-Doo Sink? [Sea-Doo Carbon Seal Issues]

Just like any other vessel, Sea-Doos can sometimes sink. But the good news is that they only partially sink thanks to a special floatation foam in their hull. Are you wondering what could cause a Sea-Doo to sink? The most common reasons are as follows:

  • Missing drain plugs
  • Loose screws
  • Improperly installed accessories
  • Hull Damage
  • Carbon seal issues

If you would like to learn more about these issues and learn how to avoid them, this post is for you!

Let’s drill into the details to see how you can keep your Sea-Doo from sinking!

Why Would a Sea-Doo Sink?

Missing Drain Plugs

The leading reason why many Sea-Doos sink is arguably missing drain plugs. These small plugs are located on the rear side of the hull. As their name implies, the drains are used for draining bilge water from the Sea-Doo.

If you forget to replace the drain plug before your next ride, your Sea-Doo can easily sink, as water will leak into the hull through these drain holes!

Loose Screws

Let’s face it, Sea-Doos have many parts below the waterline.

The pump, intake grate, reboarding step, flushing port, and many other parts are mounted with screws into the hull. And if these screws loosen, there is a chance that water will leak into the hull.

This is why you should double-check these screws after any repairs!

Improperly Installed Accessories

Aftermarket modifications are quite common on Sea-Doos. But surprisingly some of them require you to cut a new hole into the hull!

This means that improperly installed rear exhaust kits, sponsons, intake grates, or even fish finders can lead to leaks.

Hull Damage

The hull on Sea-Doos can become damaged from an accident or even wave jumping. If this happens, water can seep into the hull through these cracks. Although this is rare, it can happen at any time!

Damaged Carbon Seal

Besides missing drain plugs, another leading cause of a Sea-Doo sinking is carbon seal issues.

The carbon seal (also known as a carbon ring or carbon ring seal) is an often-overlooked key part of every Sea-Doo. This part is so important that we need to talk about it in more detail.

Let’s move on and see exactly what a carbon seal on a Sea-Doo is!

What is a Carbon Seal on a Sea-Doo?

Simply put, a Sea-Doo carbon ring is the seal around its driveshaft. The carbon ring, along with the support ring and the rubber boot, provides a waterproof seal.

You may be wondering where the carbon ring on a Sea-Doo is located.

If you take a look in the engine compartment, you can see a metal rod coming out of the engine. This rod is the driveshaft that transmits power towards the impeller.

Since the impeller is located outside, the shaft must pass through the hull. To this end, there is a hole directly in front of the pump in every Sea-Doo’s hull.

To prevent water from entering the engine compartment, engineers designed a seal to fit around the driveshaft, which is the carbon ring seal.

How Does the Carbon Ring Seal Work?

A Sea-Doo’s carbon ring seal works in a tricky way. In a nutshell, the rubber boot in this system works like a spring. It not only wraps around the driveshaft but forces the carbon ring seal towards another ring, which is the support ring. This part is a metal ring fixed on the driveshaft. As the carbon ring is tightly pressed against the surface of this ring, water can’t get into the hull.

You can see how a carbon seal works (and how to replace it) in this video:

How Can You Tell if the Carbon Seal is Bad?

It’s good to know that the carbon seal can wear out, which means that it requires regular inspection and replacement. Despite its importance, the carbon seal is often overlooked, which is why many Sea-Doos end up sinking!


This is because due to regular wear and tear or damage the two rings no longer fit together perfectly, which can cause water leaks around the carbon seal, or the rubber boot.

Because of these risks, the manufacturer recommends inspecting the carbon ring regularly.

But how can you tell if a carbon ring is bad? For your convenience, we’ve compiled the most common Sea-Doo carbon seal symptoms:

  • You find water in the bilge after each ride.
  • There is cavitation in the pump.
  • There are carbon pieces/powder around the seal.
  • You notice signs of wear and tear on the carbon ring.
  • You can see water leaks between the rings, the carbon ring and the rubber boot.

How Can You Keep Your Sea-Doo from Sinking?

If you want to keep your Sea-Doo from sinking just follow these simple steps:

  • Replace the drain plugs before each ride.
  • Never run the Sea-Doo longer than 90 seconds if it’s out of the water because this can damage the carbon ring!
  • Avoid wave jumping as it may end in a misaligned engine, which leads to carbon ring damage.
  • Regularly check the carbon seal for damage.
  • Inspect the hull for cracks.
  • Avoid aftermarket modifications.

Conclusion – Can a Sea-Doo sink?

Although Sea-Doos can sink, they don’t submerge all the way to the bottom. This is thanks to a special floatation foam inside their hull, which helps them remain afloat even if they totally fill up with water.

Why does my Sea-Doo fill up with water? – this is a question asked by many Sea-Doo owners. In a nutshell, the most common reasons for why a Sea-Doo fills up with water are as follows:

  • Missing drain plugs
  • Loose screws
  • Improperly installed accessories
  • Hull damage
  • Carbon seal issues

Thus, it’s safe to say that most Sea-Doos sink due to the negligence of the owners and improper maintenance!

Missing drain plugs or overlooked carbon seal maintenance are the leading reasons for water leaks on Sea-Doos, but other malfunctions can cause similar symptoms.

As a final word, if you want to keep your Sea-Doo from sinking, best practice is to properly maintain it according to the manufacturer’s recommendations.

The maintenance schedule is clearly stated in the owner’s manual, and with good reason. Following these recommendations is the key to keeping your Sea-Doo on top of the water!


Recent Content