When you belly flop into a pool, it can be painful because a large surface area of your body hits the water.
Have you ever attempted a belly flop into a pool? If your answer is yes, then you are familiar with the fact that it can be quite uncomfortable.
When you leap into the water horizontally with your arms and legs stretched out, it feels almost solid, like concrete. But why does this happen? How does the position of our bodies make such a difference when landing in water?
(Photo Credit : Stacey Lynn Payne/Shutterstock)
Dangerous Diving
Entering the water is not as harmless as it may seem, whether you are jumping into a community swimming pool, diving professionally, or falling out of an airplane. Olympic divers often sustain various injuries from repeatedly hitting the water at suboptimal angles.
Darren Taylor, also known as “Professor Splash,” a professional show diver, holds the Guinness World Record for the highest shallow water dive. For the reality show “Go Big,” he performed a belly flop from a height of over 26 feet into a kiddie pool with 10 inches of water.
Setting the pool on fire is purely for theatrical purposes; the real danger lies in the act of diving itself. Even with a deeper pool, a belly flop from such a height would be extremely perilous for an amateur. Even Professor Splash has reportedly suffered concussions and internal injuries throughout his career of belly flopping.
There are several factors that can contribute to the likelihood of getting injured from a fall into water, with height being the primary one.
Your position also determines the potential harm of a fall into water. There is a good reason why a swan dive is the most preferred pose when diving into a deep pool. Having your entire body pointed like an arrow is the most optimal way to enter the water.
This is the ideal way to dive into water. (Photo Credit : Jacob Lund/Shutterstock)
A belly flop occurs when you extend your arms and legs and land face first or belly first. Even when jumping into a pool from a regular diving board, a bad belly flop can result in bruising. In the worst cases, it can cause internal injuries.
Why Do Belly Flops Hurt?
When you step into a pool, the water feels accommodating, and entering feels effortless. However, when you fall into a pool, the water feels different and more solid. This sensation becomes more intense depending on the height of your fall and your body’s position.
Displacing Water
When you fall and hit solid ground, you can clearly feel the reactive force on your body, which can easily break bones. However, water is more dynamic and moves out of the way when you enter it.
The water exerts a force on your body as you displace it. This force depends on the height of your fall, your weight, and the area of contact. When you walk into water, the water slowly makes space to accommodate you, so the force exerted back on you by the water is relatively small.
When you jump into water, the water needs to move aside quickly. If you jump from a high place, your speed will be higher and you will experience a stronger resistance from the water.
In a proper dive, your body slows down at a slower rate, which means that the force exerted by the water on your body is less. However, in a belly flop, your entire body hits the water in a very short amount of time.
When you fall flat into the water, more water is displaced at a faster rate.
The larger the surface area of your body hitting the water, the more water is pushed away in a shorter time, resulting in a greater force on your body.
This is similar to falling on solid ground, where you can reduce the risk of fractures by crouching or rolling to increase the time and displacement of the impact. A belly flop is more similar to hitting a solid surface, so the water feels like concrete and causes bruises.
When you enter the water, you need to break its surface and submerge. This is challenging due to surface tension, which is stronger at the water’s surface. Breaking the surface tension is harder than moving when completely submerged.
In diving competitions, aerators are used to create bubbles and break the surface tension to accommodate and protect divers.
The larger the surface area of your body hitting the water, the more resistance the water will provide. In a swan dive, your hands create an entry point, while in a belly flop, a large surface area must be broken for entry. This can make the water feel almost incompressible for a moment as you fall into it.
To summarize, the larger the surface area of your body hitting the water, the more resistance the water will offer. With less time to slow down, the impact will be greater. Therefore, the flatter you make yourself when jumping in, the more solid the water will feel and the more painful the dive will be.
In the unlikely event of falling out of an airplane without a parachute, falling flat onto the water increases the risk of injury or even death. For painless dives, make the entry point as small as possible, such as entering with your feet or hands first. However, in a belly flop contest, feel free to spread your wings and embrace the bruises!