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Can a Jet Ski Sink? How to Keep Your Jet Ski from Sinking

Can a Jet Ski Sink? How to Keep Your Jet Ski from Sinking

Can a jet ski sink? This is something a lot of beginners worry about, and it’s totally understandable.

The answer is surprising: yes and no! It means although jet skis can partially sink, they will still remain afloat. They are specially designed to float even when totally filled with water due to floatation foam built into their hull.

Even so, gallons of water seeping into the hull can cause considerable damage, even if your jet ski doesn’t totally sink!

But you needn’t worry because jet skis rarely sink. And when they do it’s often the result of the owner not paying attention, ignorance, poor maintenance or perhaps caused by an accident.The bottom line is that these situations can be avoided if you’re careful and pay attention to what you’re doing. By reading this post and following all the basic rules, you can lower the risk of your jet ski sinking.

This post also explains what to do should you run into trouble, including how to return to shore, and what you need to do once water gets inside your jet ski’s engine.

Can a Jet Ski Sink? – Typical Causes of Jet Skis Sinking

Missing Drain Plugs

More often than not, when a jet ski sinks it’s because the drain plugs are missing. Jet skis come with drain plugs so the water can be drained from the bilge once the craft has been brought out of the water.

Sadly, owners sometimes forget to replace the plugs before launching their jet ski again. This allows water to get into the hull as soon as the jet ski is back in the water.

Beginners often make this mistake because they forget to do the pre-ride checklist and perhaps, they haven’t even read their owner’s manual. Or, if they do go through the checklist they might not be paying attention to every little detail, so they miss this step.

To avoid your jet ski sinking never forget the drain plugs!Furthermore, most jet skis have two drain plugs, and owners can easily forget this and end up putting back just one. After launching their jet ski, owners typically go back to park their car and gather up their things. When they return, water is seeping into the hull.

In the best-case scenario, they will realize this immediately. If the problem goes unnoticed, they will find out soon enough when they’re out on the water. It is now a far more serious problem because their jet ski can easily capsize or start sinking!

Due to these risks, you would be wise to follow these tips:

  • You may not need to remove the drain plugs. Depending on which model you own, you rarely need to take out the drain plugs. Even if you’ve been out in fairly rough seas, very little water probably got into the bilge as long as your hood seals remain intact. This is why many owners never take out their drain plugs. They just use a shop vacuum to suck out whatever water is in the bilge from the ride.

  • Replace the drain plugs. Even if your habit is to remove the drain plugs, why would you NOT put them back? When you’re done with your after-ride care routine and the bilge is totally dry, just replace the plugs! Also, learn the difference between the flush ports and the drain plugs because they serve totally different purposes. The black drain plugs are located at the lowest part of your jet ski, whereas the grey flush ports are located higher up.

  • Don’t forget to check the footwells and the bilge. If your jet ski has been left near the dock, check the footwells! If water is accumulating in the footwells, your jet ski may be starting to sink. If the engine is making a strange sound, you also need to check the bilge. When water gets into the hull the engine can start sounding different!

  • Consider having a bilge pump installed. When it comes to the risk of your jet ski sinking, one of the best ways of avoiding this is to have a bilge pump.

    If your jet ski doesn’t already have a bilge pump, we certainly recommend that you have one installed. Furthermore, even if your jet ski already has a factory-installed bilge pump, you might want to install a second one.

    Why? Because many factory-installed bilge pumps only work while the engine is on! A second  pump that would automatically start pumping even if your engine is off could save your jet ski!

Check for a Damaged Hull or Parts

As we’ve been discussing, even if you have a new PWC, there may be some water in the bilge right after riding. This is perfectly normal.

But you need to watch this because if you keep noticing the same amount of water, your hull may have sprung a leak somewhere. Due to this risk, you need to make a habit of regularly checking the hull. This can easily be done when you’re cleaning your jet ski.Speaking of hull leaks, it’s usually not a large hole we’re talking about. These are more commonly caused by a rubber seal not doing a proper job!

You could also have a problem near the driveshaft, since it runs through the hull. Problems can arise if the watertight protection that surrounds the driveshaft becomes damaged (this depends on the model).

The problem could also be a broken water hose as intercoolers and open loop cooling systems are still cooled with raw water. If you have a broken hose it will leak water right into the hull!

Important tips to follow:

  • Regularly check your jet ski, including the hull. Thoroughly check the bilge as well after each ride. If you see a lot of water, that doesn’t bode well. Have your jet ski inspected before taking it out again!

  • Make sure to cool your jet ski. If your jet ski is out of the water, do not run the engine any longer than 15-20 seconds.

    Even if you use a garden hose to cool your jet ski, the watertight protection surrounding the driveshaft won’t be cooled down, even though it should!

    This is exactly why every owner’s manual says not to keep the jet ski running too long when it is not in the water.  The RPMs should be kept low to avoid overheating.

  • There is never any reason to take out the flotation blocks (foam) located within the hull. The newer jet ski models are designed to float even if they fill up with water. This is due to the flotation foam and why it should never be removed.

  • Never leave your jet ski overnight in the water. This is when it would be most vulnerable to sinking. It is quite typical that an owner who leaves his jet ski overnight in the water will come back the next day to find it sunk.

    Anytime you leave your jet ski in the water, there must be someone watching it, even if it is just for a short time!

Improper Maintenance

If you do not properly maintain your jet ski on a regular basis, you’ll start having problems, some of which could be very serious. This is why you must follow the recommendations in your owner’s manual for servicing and winterizing.At the same time, you need to know that no matter how careful you are about having a professional service shop or dealer do the work, mistakes can be made. The wrong parts could be installed or if you have a missing or loose bolt, a leak can occur.

Important tips to follow:

  • If you know how to maintain/service your jet ski yourself and have all the right tools, great! But if not, you need to take it to your local dealer or to a professional service shop.

  • Check the bilge for leaks. It is very important that you inspect the bilge for any leaks after you get your jet ski back after having a regular maintenance or repair. And for the same reason, check the bilge carefully after your first ride of the season as well!

  • Think hard before deciding to modify your jet ski or have performance parts installed. Doing this could void your warranty and also cause leaks.

Improper Riding & Flipping Your Jet Ski Over in the Water

No matter what you’ve heard, even high-performance PWCs are not designed to jump waves.

Wave jumping can break engine mounts and/or other vital parts on your jet ski. This could result in water leaking into the hull and all kinds of other mechanical problems as well.

Important tips to follow:

Improper Towing

There could be any number of reasons why your jet ski would need to be towed by another jet ski or a boat. It could have run out of gas, be malfunctioning or have accidently sucked up a rope or some debris from the water.In all of these cases, your jet ski will have to be towed back to shore before you can handle the problem. But you need to be aware that improper towing can result in water being forced into the engine as well as the hull through the exhaust system.

Important tips to follow:

What to Do If Your Jet Ski Starts Sinking

Even if you take all the precautions discussed above, water could still seep into your jet ski’s hull. There is no need to panic. Depending on the water level in the hull, this may not be serious. We’ve compiled a step-by-step guide for what to do when your jet ski is sinking:Important steps to follow:
  • Remain calm. It is very important that you remain calm if you notice your jet ski starting to sink. At the same time, you need to act quickly! All the newer jet skis cannot sink completely, so don’t worry about this.

    The bad news is that the bow (nose) of your watercraft is the only part that can stay afloat above the surface of the water. The other parts of your jet ski, including the engine, will sink under water!

  • Immediately start the bilge pump. The moment you notice a significant amount of water in the hull you need to immediately START the bilge pump (if you have one) and TURN OFF the engine.

  • DO NOT restart the engine. Never restart the engine if it’s under water or if the water level is getting close to it. If there is a lot of water in the hull, it is best to immediately stop the engine and get your jet ski towed back to shore as soon as possible. While waiting for your tow, try removing as much water as possible with a baler. DO NOT touch the engine as it’s probably hot!

  • DO NOT try riding back to shore. Do not try starting your engine so you can ride back to shore if you have no idea why you’re sinking! If a leaky water hose is causing the problem, running the engine will only make your jet ski sink faster!

  • Have your jet ski towed back to shore. Your best option is to have a boat tow your jet ski back to shore or another jet ski. If there is no one nearby to help you, contact a professional towing service like SeaTow.Be careful when you perform all these steps. There is no need to panic and risk getting injured!

What to Do Once Your Jet Ski Has Already Sunk

  • Drain all the water out. Once you’re back on land, put your jet ski up on the trailer. Pull the drain plugs out to drain the water out of the hull. Be patient because it will take time for the water to drain out completely.

  • DO NOT start the engine. Once you’ve drained out the hull, you may wonder whether the engine runs okay and be tempted to start it. Don’t try that! You still have no idea whether or not water seeped into the engine! If you try starting the engine when water is still in the cylinders it can cause hydro-locking, which can completely destroy your engine. Whether there is water in the engine or not, you can check the oil at this point.

  • Remove the dip stick to check the oil. If water has seeped into the oil it will look like a caramel colored smoothie. The consistency will also be a lot more like liquid than oil and it may even drip all over from the dip stick. If the liquid dripping off the dip stick is caramel colored, light brown or tan, it’s clearly a bad sign, so you need to act immediately.

  • Transport your jet ski to the dealer. If the oil tells you that water has seeped into your engine, you must immediately take your jet ski to the dealer or a professional service shop. Urgency is key because things are now rusting inside your engine and it will soon become junk. It is even more urgent if your jet ski sunk in saltwater because it’s much more corrosive.

    Your engine can be saved in many cases, but you have to act as quickly as possible. The absolute worst thing you can do is let your jet ski sit there with water in the engine!

    Even if your oil looks okay and it doesn’t appear that water got into the engine, it is still very important that you NOT start the engine before taking it to a professional for a complete inspection. If water got into the hull, it can damage other things besides the engine.

     The dealer will also check the gas, because it’s important to make sure that water did not get into the gas tank. The electrical system will also need to be checked to ensure that everything is working well and was not affected by the water. It is often best to replace the battery in these cases, even if it seems okay.

     Just remember that you need to take your jet ski to the dealership immediately if a significant amount of water seeps into the hull!

  • Remove the waterlogged seats. Your seats are going to be really heavy if it’s soaked with water. The problem is that there is no good way to drain all the water out of your seats. All you can do is remove them and stand them up to drain out as much water as possible.

  • Call your insurance company. Assuming your jet ski is insured, which it should be, you’re your insurance company to see what’s covered in this situation. Insurance sometimes covers an issue like this, but not always. Each situation is different, so it all depends on how this happened and what you’re covered for under your policy.

  • Consider buying a new jet ski. It’s not surprising that some owners in the aftermath of sinking their jet ski insist on having a new one. They are convinced that their old one will never fully recover from being submerged, which is understandable. If all the parts and equipment onboard have been wet, everything will likely rust prematurely. It’s impossible to know what issues will arise, including mold growing in the seats, mechanical issues and who knows what else?


It is possible for jet skis to sink, but not totally because their hulls are designed with floatation foam built into them. So, the bow will stay afloat above water, even if the jet ski fills with water.

However, if a substantial amount of water seeped into the hull, your jet ski can be damaged in multiple ways. The most vulnerable part is the engine. Since there is no way to determine whether water has seeped into it or not, it is best that you NOT try starting the engine. You need to immediately transport your jet ski to the local dealership.

Let the professionals check your engine and everything else that may have become water damaged!

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