5 Common Reasons Jet Skis Sink (and what to do about it)


Many jet ski owners, especially those who have just purchased their first jet ski, worry if it is possible for their jet ski to take on water and sink. Although the floatation foam in the jet ski’s hull makes a complete sinking unlikely, taking on water is a very possible thing to have happen and can cause just as much damage. This is the absolute last thing that any jet ski owner wants when they are out enjoying the water on their jet ski. 

Why does my jet ski fill up with water? 

There are a couple of reasons as to why a jet ski would take on water, which includes missing or damaged drain plugs, a variety of damaged seals, improper maintenance, or inappropriate use of the jet ski itself. Many of these reasons can be easily prevented with proper maintenance and use before, during, and after using a jet ski.

Jet ski owners can easily prevent their jet ski from sinking by regularly checking over their watercraft before each use and using it properly when they take it out on to the water. This will help jet ski owners avoid hazardous situations while out on the water and costly repairs to fix the damage caused to their craft. It is important to be very careful and pay attention to the needs of your jet ski each and every time that you plan on using it. 

5 Common Reasons Jet Skis Take on Water

There are several main reasons that could cause a jet ski to take on water, and most of them have to do with mistakes made by the operator of the craft, often before the jet ski ever goes into the water.

Missing or Damaged Drain Plugs

This is the most common cause for a jet ski to sink. All jet skis (besides some older stand up models) come with drain plugs, which are used to drain out any of the water that the jet ski may have taken on while being used.

After a day of riding, take the jet ski out of the water, put it on a trailer, and remove the drain plugs in order to let the water drain out. If the drain plugs do not make it back on to the hull properly, the water will flow freely into the jet ski the next time it is put into the water. This will cause it to take on water and eventually sink.

After draining the water from the jet ski, the plugs are commonly left out to let the hull naturally dry out. These need to be put back and secured tightly before you put it in the water again. If you think you might forget to put the plugs back later, it might be better to replace them immediately after you finish draining the water from the previous use. Alternatively, if your jet ski doesn’t take on much water during use, you may not even need to remove them at all.

Most jet skis come with two drain plugs, though there are also plenty of models that have only one. It is important to know how many of these are on your model and exactly where they are located. On my Honda, there are two located on the rear. On my older Sea-Doo, there is one to the side of the jet pump.

Because the number of plugs can vary between models, it is possible to secure one but to forget the other. If you are purchasing your first jet ski or upgrading to a new model, make sure that you consult the jet ski salesperson and the owner’s manual to ensure that you know the location of all drain plugs on your model.

It is also possible for drain plugs to get damaged or to wear out over time. Even if they are secured in place, they may not be secured tightly enough to prevent the intake of water into the vessel once submerged. The slightest adjustment could prevent this, as can making sure that the plugs fit properly. 

You will want to check the condition of your plug(s) and look for cracks after using your jet ski. It is also smart to purchase an extra to have on hand in case one of your plugs does break or get lost.

Drain Plug Check-List:

  • Know how many drain plugs you have and always check to make sure they are all fastened tightly in place before taking the jet ski out onto the water. This is a quick check that can save you lots of hassle and costly repairs caused by taking on water.
  • Double-check to ensure that all of the drain plugs are not damaged, stripped or not sealing as they should. After every use of the jet ski, unplug them to drain the craft. While doing this, take a look at all of your drain plugs to assess their current state. If you are unsure about their condition, go ahead and take them into a jet ski service shop and they will be able to assist you in buying new ones or checking out the ones you have. 
  • Replace the drain plugs when necessary. If they begin to look stripped or worn down, this would be an ideal time to have them replaced. They are fairly inexpensive to purchase when compared to the cost of sinking the jet ski. 
  • Extra Credit: Think about attaching a bilge pump for your craft. This additional piece will work to remove any build-up of water that may be present in your engine. It will suction it out of where it does not belong to prevent your jet ski from taking on water. 

Damaged Parts

It is also possible that the jet ski could have taken on water due to a leak somewhere in the hull, water fittings, or even the seals. If a jet ski were to hit anything on the water, such as a rock, the land, or even a buoy, this could cause there to be scrapes or holes that are punctured into the exterior layer.

Sometimes, the hull can be damaged with improper beaching techniques. Beaching your jet ski is a good way to store it temporarily, but if you are close to shore and hit a rock, or are constantly beaching on a rocky bottom, it can cause cracks in the hull.

Any damage that occurs to the hull, whether big or small, will cause water to leak into the jet ski itself. It does not have to be a large hole; sometimes, a simple scrape or a faulty rubber seal will be enough to allow water inside. For an in depth tutorial to fix hull damage, here is our guide.

Alternatively, a loose or damaged driveshaft seal can cause your ski to take in water. This may happen if it is worn down or has a rip. To maintain your driveshaft, always grease per the manufacturer directions.

Also, if there are any pump fittings on the ski, make sure they are tight and sealed.

Another common part issue that can cause a jet ski to take on water is a faulty hose clamp. This clamp, which attaches a hose from the jet pump to the water box, can break or come loose, and if it does, water will start filling up the engine compartment. When you take your jet ski in for regular maintenance, have them check the hose clamp to make sure it is secure and in good condition.

In addition to damage that can happen when your jet ski is being used, you can also accidentally damage your jet ski by mounting it incorrectly on the towing trailer. One of the ways this happens is by having your ski pulled up too far. If any part of the jet ski is rubbing against a metal part of the trailer, it can wear a hole in the hull.

Parts Check-List:

  • Always check the condition of the craft before and after taking the jet ski on the water. Even if you did not hear or feel a collision with something while using the jet ski, that does not mean that this did not happen. Damage can also happen in transit to the water, so you will want to check it after transporting it as well. 
  • Check rubber seals and replace as necessary. Always check rubber seals in the hull, especially the driveshaft seal, as these are prone to leaking. If you see signs of wear or tear, replace them before you use the craft again.
  • Cover the jet ski while it is not in use to protect it from the elements. If not covered properly, your jet ski can crack from the sun or heat. Use a cover, place it under an awning or in a garage, and try to keep it out of the sun if possible.

Not Taking Care of the Craft

As is true with owning any piece of high-tech equipment, the most important part of owning a jet ski is keeping up with the maintenance. Whether you’re using your jet ski regularly or not, maintaining a jet ski is something that should happen regularly regardless of the amount it is being used. Consult your owner’s manual to see what regular maintenance is required or consider taking your jet ski into a service shop. 

For more information about jet ski maintenance and maintenance tips, see here.

Maintenance Check-List:

  • Read the owner’s manual very carefully and stay on top of regular maintenance. Be sure that you are aware of maintenance that is required to protect the jet ski and keep it functioning at top-notch. At the bare minimum, this will involve changing the oil and replacing the battery occasionally. When not in use for several months, follow procedures for winterizing your jet ski.
  • Grease the fittings. Always grease any fittings that separate the inside of the hull from the water. This includes any pump fittings, driveshafts, steering cables, etc.
  • Take your jet ski to a dealer or licensed repair for scheduled check-ups. If you are unaware, unable, or unwilling to do the maintenance required for your model, be diligent in taking it in for regular check-ups to ensure that everything is functioning as it should.

Incorrect Towing on Land and in the Water

Jet skis should never be stored in the water long-term. Because of this, most people need to tow their watercraft to and from the water, at least occasionally. When towing a jet ski, it is important for the jet ski to be loaded onto the towing trailer the right way so that it sits correctly. If it is not, it could cause damage to the hull or to the trailer. This is especially important if your jet ski is stored on a trailer between uses. Check out this helpful video on how to load a jet ski onto a trailer correctly.

It is also possible to damage the jet ski if it is being pulled in the water. When the jet ski is being towed in the water, preventing the engine from filling with water is a major concern. Consult your owner’s manual to see what kind of precautions and procedures are recommended when towing your jet ski in the water. 

For example, when I tow my stand up, it will submerge if I start to go too fast. The best way to tow it is to hold the rope close in towards the towing craft, go however fast you want, and then let the ski rope go bit by bit. Most of the time you should not tow any faster than idle, but in an emergency, you may have to go somewhere quickly.

Towing Check-List:

  • Get a towing trailer that fits your specific jet ski and follow traffic laws to protect your craft while driving it on the roads. Whenever the jet ski is being towed on land, ensure that it is strapped down properly to prevent any slipping, sliding, or the possibility of it coming off the trailer altogether.
  • Read your owner’s manual before towing in the water. If you need to tow in the water, you need to do it correctly or the jet ski may sink. Your owner’s manual will explain how to tow the jet ski properly, including any limitations on speed and use of proper signaling devices. Learn these procedures and have a plan in case of an emergency before ever going out on the water with your jet ski.
  • Have a towing plan for if you get stalled in the water. If you have a friend or family member on a boat who can come get you, great. Make sure you have a way of contacting them or signaling to them that you need assistance. If you don’t, you should research local towing services before taking your jet ski out on the water. Many companies, such as Boat U.S., offer basic towing plans for as little as $24 a year. 

Inappropriate Use and Collisions

Jet skis can be a lot of fun as long as they are used correctly out on the water. Owners need to be aware of their surroundings and the actions of other boats to prevent collisions. Just as there are rules for the road in a car, there are rules on the water when using a jet ski. Familiarize yourself with these rules to help avoid getting into any collisions. 

Other boats and jet skis are not the only dangers out on the water. It is very possible to damage your jet ski without anything else being involved. Jumping over waves and turning too quickly (either on purpose or by accident) are improper uses of a jet ski and could result in damages to the craft or even a flipped jet ski. If your jet ski flips, it will begin to take on water very quickly. Use a jet ski within its limits to make sure that it is around for a long time. 

Proper Use Check-List:

  • Be aware of your surroundings. Constantly be on the lookout for other boats, jet skis, swimmers, wildlife, or debris in the water. Running into any of these could cause harm to the rider, the jet ski, and other people or boats. In the end, this could be a very costly mistake to make. Sometimes, the most dangerous situations are not ones that are caused by you but those that are caused by the other reckless people who are not following the rules, and you need to watch out for them too.
  • Know your model’s limitations and don’t showboat. Sometimes, jet ski owners will try to do flips and tricks that their jet ski was just not designed to do. This can result in a flipped jet ski, which can ultimately damage a jet ski very badly. If your jet ski is flipped, make sure you know which direction you are supposed to flip it back over. Most have a graphic with directions, but trying to right the craft the wrong way can lead to a hydro locked engine.
  • Advanced: If you are doing tricks such as submarining the jet ski, make sure you let your jet ski bilge pump pump the water out before you try the trick again. This will prevent you from getting too much water in the hull.

Warning Signs that Your Jet Ski is Sinking

If your jet ski flips or starts rapidly submerging into the water, it’ll be pretty obvious what’s happening, but with slow leaks, there are some more subtle signs that your jet ski may have started taking on water. These include:

  • Water accumulating in the footwells.
  • The engine making odd sounds. If this happens, check the bilge to see if you see water accumulating.
  • The jet ski stalls out on the water. Though this can happen for a number of reasons, if the gas tank isn’t empty, a leak is one definite possibility.
  • Water in the bilge.  After riding, there’s going to be a bit of water in the bilge, but if you are always noticing a significant amount, it could be a sign of hull damage.

So Your Jet Ski is Sinking. Now What?

Being on a jet ski while it is sinking can be a very scary situation. However, it is important to follow certain steps and protocols to ensure the safety of both the jet ski and the rider. Follow these steps if you are ever in this predicament in order to stay safe.

Stay calm. The most important thing that you can do is to stay calm during the incident. When a jet ski owner panics, is it likely that they will forget what they need to do and risk hurting themselves or the jet ski more than necessary. 

Turn off the jet ski’s engine (and don’t turn it back on). This single point cannot be stressed enough. Jet skis were not meant to be turned on when there is a lot of water in the hull. Turn off the engine and keep the engine off. Do not try to turn it back on at all. If you have a bilge that runs off of the motor, you may want to divert from this suggestion and leave your engine on to pump out the water.

Turn on the Electric Bilge Pump. Most jet skis come with a basic siphon bilge pump installed, but as stated above, many of these require the engine to be running in order to operate. Consider installing an electric bilge pump in addition to the standard pump. Electric pumps can run while the engine is off, which can save your jet ski from major damage if it starts to take on water.

Don’t flip the jet ski over. Maybe you think the hull is damaged and you want to see if there’s a crack somewhere. Don’t. Flipping the jet ski over will flood the engine with water and cause more damage to the watercraft.  Wait till the jet ski is out of the water to inspect the hull for damage.

Find a way to get back to the shore as quickly as possibleHopefully, there will be another jet ski or boat around that can safely tow you back to the shore. If there is no one around, then you will need to call someone for help. Don’t try to get the jet ski back to shore by yourself.

Keep safety equipment on board: A sinking jet ski is a good reason to have a folding paddle, air horn, safety flag, and waterproof phone case with you at all times. Store these on your jet ski in case of an emergency.

Repairing a Sunken/Water-Damaged Jet Ski

Once you get back to dry land, it is important to act quickly in order to prevent permanent damage to your jet ski. 

Follow these steps, immediately:

  • Release the drain plugs and let the water dry out. The first thing you need to do is get the water out of the jet ski by removing the drain plugs.  Also, be sure to remove the seats and hull covers so the ski and electronics can dry out over the next week or so. Place the seats in an upright position to allow as much water to run out as possible.
  • Check the oil. If the oil is a light caramel color or if it looks more liquid than oily, take the jet ski to a dealer or a repair shop right away.
  • Call a dealer or repair shop. Even if you don’t think too much water got into the vessel, call a dealer or repair shop to talk with an experienced mechanic who can help you determine the next steps to take. They may recommend you bring the jet ski in to be evaluated, or they may give you some tips for simple repairs you can do at home.
  • If you are comfortable doing basic maintenance on your jet ski on your own, remove water from the engine: If your engine sucked in water, you will want to remove your spark plugs and run your starter. This will purge the water out of your cylinders. Next use a fogging oil and spray in the cylinders and carburetors. For anything more advanced, call a dealer or repair shop.
  • Call your insurance company. It is important to have jet ski insurance for situations like these.  You will need to consult your specific provider and they will be able to assist in filing a claim and getting the money needed in order to finish the repairs that are in order. Some water damage may be covered by your insurance, while others, especially do to improper maintenance or use, may not. 

How do I prevent my jet ski from sinking?

Because there are so many different reasons a jet ski can sink, there are many different safeguards that should be taken in order to prevent your jet ski from sinking. For detailed instructions on each of these safeguards, see the various checklists written above. 

The most important tips to remember are:

  • Be extra diligent checking over the watercraft every time before it is taken onto the water (check drain plugs and rubber seals, inspect the hull for cracks, make sure safety equipment is on board).
  • Get regular maintenance done on your jet ski to make sure it is in good working order.
  • Make sure you are towing your jet ski correctly both in and out of the water.
  • Practice safe operation while in the water (avoid excessive speeds, jumping waves, and turning too fast) and watch out for other people, boats, and other hazards.
  • Consider adding an aftermarket bilge pump. This will work with your stock model to pump out excess water as fast as possible.

Buying/Selling a Jet Ski that Has Been Sunk

Just because a jet ski has sunk or taken on water doesn’t necessarily mean it is junk.  When properly repaired, a jet ski that has experienced water damage can still run well for years to come, especially if the accident happened in fresh water.

When buying a used jet ski, it is a good idea to ask if the jet ski has ever sunk or experienced water damage. If so, try to get more information about what happened and what was done to repair the jet ski afterward.  You can also check the seats; if they are heavy, the jet ski likely experienced water damage at some point. Ask about any additional warranties that exist on repairs done and, if possible, test the jet ski on the water before taking it home to ensure that it runs properly.

When selling a jet ski that has experienced water damage, be honest about the circumstances of the accident and keep a record of repairs done that you can share with prospective buyers. If you took the right steps to have the jet ski properly repaired, there’s no reason why it can’t be re-sold later, but it is important to be upfront about it.

Conclusion

Using a jet ski in the water can be a fun and exciting activity that the whole family can take part in and enjoy! However, it is essential that the jet ski is properly taken care of before, during, after, and in between every time it is used. This will help jet ski owners to avoid any headaches that could possibly come from a sunken jet ski, and make sure that all of your future jet ski outings are worry-free and fun! 

Eric

I have been an avid boater / jet ski fanatic since I was a kid.

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