Why shouldn't we hold our breath underwater?

[Akimbo]

"Never hold your breath" is actually a short-cut phrase to tell new students "always leave your airway open." ...

Not exactly. The phrase that was in books and my dive class in the early 1960s was essentially “Never hold your breath on ascent”. Of course students learned a lot about barotrauma during their six class-room sessions.

The complete phrase we learned in my class was “Never hold your breath on ascent or your lungs will explode in your chest and you will die a horrible death”. Totally accurate and made a lasting impression.

 

[drbill]

During initial instruction it is often convenient to use absolute statements like "Don't hold your breath" to simplify an issue and make a strong point. As a videographer, I often hold my breath or breathe very slowly when trying to film a subject. However, when I do I am usually on the bottom with my BCD evacuated and don't move vertically. If I am in a vertical position in the water column filming a subject mid-water I try not to hold my breath but breathe in short breaths to prevent swings in depth. Of course that can incur CO-2 retention issues.

 

[sipadiver]

CO-2 retention issues? I've heard from some old divers that if you hold your breath underwater - brain damage can occur because you aren't circulating the air, and the trapped compressed air expands and damages brain cells. Does that happen?

 

[RJP]

I've heard from some old divers that if you hold your breath underwater - brain damage can occur because you aren't circulating the air, and the trapped compressed air expands and damages brain cells. Does that happen?

Nope.

 

[tphelps]

My solution: get a rebreather! Your buoyancy wont change breathing in a closed system! (plus you get closer to wildlife!!)

 

[DevonDiver]

But what if we are stationary,...

How often do you see that?

 

[String]

Holding breath underwater is not a bad thing and im some cases its essential. The danger with new divers is holding breath generally means full lungs so becoming positively buoyant.

Holding breath AND ascending at the same time is a bad idea, simply holding breath on its own is fine.

 

[Adventure-Ocean]

We hunted using scuba for years. We not only held our breath often during a dive, we often were separated from our buddies so we had a chance to find a fish. We breathe soft and slow and hold our breath for two reasons. One is not to scare the fish and the other is to get a bit more time from our tank. The rules taught for open water certification must be totally conservative since failure to instruct properly could present legal problems. After getting more training and experience you'll learn more about the diving rules and why they are taught to beginners. The rules are not laws. You enter the water and dive at your own risk. When you start stretching the rules you normally are increasing the risk. Again, it's totally up to you. I dove many years with some very aggressive divers. A few of them had gotten bent at least one time and one friend had to give up scuba because he dove too deep too long too many times. We are all taught the dangers when we get certified. The question is always how safe do I want to conduct my dive. Hopefully your choices will lead to a lifetime of great diving.
Adventure-Ocean

 

[rhwestfall]

Same reasoning as exhaling and going "Ah" when doing a CESA, as opposed to just ascending with airway open.

I prefer DumpsterDivers method: scream "sheeeeeeeeeeeeeet" on your way up......

 

[Dsix36]

If you hold your breath for too long, you run the risk of actually passing out. Although this is not a life threatening situation, when the regulator falls out of your mouth and you start sucking water, drowning becomes a serious concern. Just sayin'