Do Car Seats Float? And How to Escape from a Vehicle

Do car seats float and is this a necessary safety feature? What happens if you’re the owner of a popular brand and the greatest disaster happens to you, landing in the water while sitting in the car? What do you do then?  

I dug into this topic as a parent who likes to be prepared to protect my family, as an engineer and physicist who’s curious about some natural phenomena. Like whether an object sinks.

In this post you’ll find (hopefully) all the information you need: the physics behind car seat floating (or not), what a world-known expert in Aquatics Safety & Water Rescue has to say about popular brands based on his test. And how to escape from a submerged vehicle. 

Here’s the Answer if Car Seats Float

In simple terms, yes, a car seat does float but it hasn’t been specifically designed that way. In fact, the foam padding inside of the seat plays a crucial role regarding buoyancy. During a study done by Gerald Dworkin of Lifesaving, it was found that most car seats float. Their tests on three popular child safety seats showed that they remain buoyant to support the child manikin for 10 minutes.

Why Care if Car Seats Float?

If your car is submerged in water, the car seat plays a role in how you and your child will survive this ordeal. 

Of course, while the car seat is attached to the car, it wouldn’t float. Therefore, after impact, you would need to cut the seat free or release the seatbelt or latches keeping it in place. Then, the car seat can float to the top with your child safely secured in it.

Another condition that has to be satisfied is that your car seat has to be constructed in such a way that it can float. Thus, research the brand to find out or keep reading this article.

Physics of Car Seats Floating and Problems With Theory

The only way to really know if a car seat floats would be to do a real experiment. 

Buoyancy happens when the upward buoyant force is greater than the force of gravity acting on the submerged seat. To theoretically calculate the buoyancy of the seat you’d need to know the volume of the car seat which is not published by the manufacturer. 

This is because manufacturers only state the outside dimensions. This is done to assist you in making sure that the car seat will fit in your car. But this doesn’t help with testing buoyancy.

Even if we could measure the volume by submerging it into water, then measuring the displaced volume of water, the end result would still be incorrect. This is because you will never know how much water can be absorbed into the car seat as it floats which will then change the weight and volume of the car seat.

Therefore the only way to know for sure if your car seat floats is to do a real experiment.

Experimental Evidence of Why Car Seats Float

One of the main reasons why I reached out to Gerry Dworkin is because he is a consultant in the area of Aquatics Safety & Water Rescue at Lifesaving Resources. He’s a world-class expert who got featured in NBC’s Today Show, ABC’s Good Morning America, The Discovery Channel, etc. 

He did an experiment to see if car seats float.

Here is a statement by Gary himself:

“This was not a funded study and we worked with a very limited budget. But, we were able to obtain 3 very popular child safety seats and we secured a submersible manikin into each. We then placed the child safety seat with the manikin secured to it into a pool. In each of the 3 cases, the child safety seat was sufficiently buoyant to support the child at the water’s surface and sustain its buoyancy for 10 minutes. This was not a formal study and, as I mentioned, it was not funded in any way.”

When it comes to testing the buoyancy of a car seat, there is only so much you can do. It wouldn’t be logical to risk your child’s safety which is why the test was done with manikins. 

If you really wanted to try this experiment at home I would suggest using something that weighs exactly the same as your child, this way you can get as close to the real thing as possible. I know, it’s cumbersome.

Parts of a car seat that helps car seat float

It may help if you understand what helps a car seat float. The most important thing to consider is the foam inside the chair. 

The foam types often differ between seat types. A booster seat may be much different than the seat you purchased for your newborn. Also, foam isn’t specifically designed to float. Other characteristics such as comfort levels and flame resistance are often the priority. So, quality foam doesn’t guarantee buoyancy. Polyurethane is popular, but other substances are also used. Evlon is very dense, while open cell foam facilitates air and moisture flow. 

The frame – often plastic – will affect buoyancy. Even the outside fabric plays a role. If it’s waterproof it could help prevent the foam inside from quickly taking on water and getting heavier. 

Here’s an article that describes all the parts of a car seat if you want to read more about this topic.

Do Infant Car Seats Float?

Upon asking Gerry this question, he gave me this response: “I honestly have no idea who the manufacturers were. But, the seats were for infants and young children.”

It would be safe to assume the infant car seats float too because they would also be made with a foam filling. There is no guarantee that the foam filling will be enough to help assist in the car seat floating while your infant is in the seat. But for a short amount of time it can help in a scenario where the car seat does need to float.

Do Britax Car Seats Float?

When deciding on which brand you want to use, there are many features to consider. For example, you research user friendliness and safety by reading reviews.

Fortunately, most websites have the information on their FAQ’s page. I did this to find out whether or not Britax car seats float. However, there is no definite answer.

Britax doesn’t give much away when it comes to the materials used other than the foam being energy absorbing. So, during an accident the foam will take most of the impact.

Of course, this is beneficial but there is no evidence that Britax car seats float. It could be assumed that the car seats can float due to the seat containing foam but there is no solid proof.

What to Do If You’re in a Submerged Vehicle

There are a few emergency protocols we should all be aware of and that includes knowing how to get out of a submerged car. This can be a very dangerous situation for everyone involved which is also why everyone that travels by car on a daily basis should know what to do.

Here’s a video that gives you the instructions:

It’s said that the time it takes a car to submerge completely is anywhere between 30 seconds and 4 minutes. During the ordeal, it can feel a lot shorter than it actually is. What impacts the sink time are intact seals and weather seals on your windows.

Escape paths from a submerged vehicle

It’s important to note that it can be almost impossible getting doors or windows open so breaking a car door window would be your best option. The rear window is usually made out of tempered glass so it should shatter rather easily. A decision would need to be made fast though as time will not be on your side.

Tools you need to escape

Depending on the water depth, there are a number of things that could happen. The car can sink straight down and land on all four wheels or it could turn upside down and land on the roof. So it’s important to act quickly when you hit the water.

It would be in your best interest to purchase a life hammer device and have it in your car at all times. This item can assist you in breaking the glass quickly. Also, you can use the included blade to cut seat belts as you may struggle to unclip them, either due to them jamming or you panicking. 

Planning the escape

The best policy is to first break the window and create an exit path using the life hammer device. Then you turn to your family members and help them out one by one. 

For children you unbuckle or cut them loose, oldest to youngest and push them outside. If the child plus the car seat can fit through the escape hole, a floating car seat will be a huge help, since it will take them safely to the top. Alternatively, you’ll need to unbuckle or cut the child loose to help them exit. 

It may be a good idea to practice unbuckling and releasing without looking, so you can do it in low visibility conditions under the water too.

Final Thoughts

As you can see above, evidence shows that many car seats do float. However, if you’re in a car crash and you fall into water, it’s probably safer and more practical to leave the car seat behind. Unfortunately, in order to get the baby car seat out you’ll need a quick release seat belt which most cars don’t have. 

That’s why you need to practice fast seat belt unbuckling in case of an emergency. Or keep a life hammer in your car capable of breaking windows. These life hammers also have a sharp knife that can cut seat belts so you can release the car seat quicker. 

Make sure you practice your strategy well in case of an emergency. You could perhaps turn this into a game with your little one so if you’re in an emergency situation you can keep your baby calm when releasing the seat from the car.

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