What happens when you hold your breath while you scuba dive

By Corné LigtermoetFebruary 25, 2019

Everybody knows there are some risks when you are scuba diving. During your first introduction to scuba diving you will be told, NEVER HOLD YOUR BREATH. But what happens when you hold your breath while you scuba dive?

First of all I want to say that diving isn’t a high-risk sport when you follow the rules. When you are following the rules, the risk of getting hit by a falling coconuts is a bigger risk than having a scuba diving accident.

To read the original article on 50ft Below, please visit their website here.

Can you hold your breath while you scuba dive?

The only answer is, NO you can’t hold your breath while you scuba dive. Well it is possible but it isn’t really wise to do it. So what will happen when you do it. First let me explain what the water pressure will do to air when you head down underwater.

Physics of the ocean

During your first introduction to scuba diving you will be told, NEVER HOLD YOUR BREATH. There is a reason for this. The deeper you descend, the more the pressure increases. For example, when we take a balloon on the surface and we fill it up with air. While we descend to 32 ft/10m the pressure will increase from 1 bar/ 14.7 psi to 2 bar/29.4 psi, the balloon will decrease in volume. In the example of a descend to 32 ft/10m the balloon will be the 1/2 of the volume then on the surface.

Every 32 feet/10 meters we descend we have a 1 bar/14 psi increase of pressure. Check out the table from SSI about the pressure increasing underwater.

So what happens when you hold your breath?

When you scuba dive you are adding air to your balloon or you can say lungs. So when you are diving at a depth of 10m/33ft you have 2 bar/29.4psi of pressure. When you fill your lungs completely with air and as long as you keep breathing this air can escape the natural way. But when you hold your breath while you ascending to the surface the pressure is decreasing to 1bar/14.7psi. So the volume of the air gets bigger and it needs to escape. If it isn’t the natural way, it will find a way to escape. Check the video on top so you can see what will happen to the balloon.

So scuba divers: ALWAYS BREATHE UNDERWATER!