Mr T's Wild Freedive

[IncreaseMyT]

Or exhales, same way a SCUBA diver uses lung volume changes to rise or fall in the water column.


Bob

I agree, but then again now you need a another breath before you go up or you will probably black out. SO as you said, that person becomes a scuba diver.

 

[Stoo]

Ya. My thought exactly. ;-)

 

[IncreaseMyT]

I don't understand what is so hard to understand. The whole point of free diving is to breath hold. If you are trying to tell me you can go down and take a breath of air off a reg and then just continue free diving like nothing happened then it is obvious to me you have never even contemplated it before let alone done it.

You can feel the difference at just 25 ft, but it is not substantial there. So you can roll your eyes and shake your head, but it just makes you look uninformed and inexperienced.

If you are past your neutrally buoyant depth, then you will go from negative to positive in a single breath. The deeper you are, the bigger the swing that is.

 

[zixzax]

If you are past your neutrally buoyant depth, then you will go from negative to positive in a single breath. The deeper you are, the bigger the swing that is.

I think you are quite right on this. A deep free diver may shoot up after one single inhale unless he holds up to something. If he is holding the scuba diver, I guess it is also a danger for that generous guy, who might be pulled up at a too fast speed.
As a newb I never experienced that and so I launched this post. It is just for discussion. Different opinions bring us together to enjoy thinking.
Thanks for your comments and enjoy diving with your son

 

[Mark IV]

It's highly unlikely the relatively small amount of positive buoyancy incurred from a single breath, could possibly result in that freediver pulling the scuba diver up, especially at, "too fast a speed".
Remember, the freediver started his dive with normal lung volume, and was still able to get down. All the scuba diver could provide was a return to that same normal lung volume. The freediver isn't taking on any "extra" air, as it pertains to buoyancy, he's just going back to a normal (sized) lung-full of air. (again, buoyancy is affected by the volume of air, not how many molecules of air are compressed into a given space.)

 

[IncreaseMyT]

It's highly unlikely the relatively small amount of positive buoyancy incurred from a single breath, could possibly result in that freediver pulling the scuba diver up, especially at, "too fast a speed".)

Here is the thing though, it is not a small change. Let me explain to you what happens when you free dive so that this makes more sense.

The first thing you wanna do when you free dive is adjust your weight. You will want to put on enough weight so that with a full breath you are still positively buoyant, basically you want your chin to touch the water in a vertical position. For me in salt water this is about 8 pounds, if I let out out breath, I will sink. I would guess I am 2 pounds or so positively buoyant (maybe more though).

So now I have got my weight on, and I am doing my breathe up. I take a deep breath and duck dive, swimming down the line. As I pass about 17 ft I start to become negatively buoyant. The deeper I go, the more negatively buoyant I become. Once you pass 60 feet you could be as negative as 4-5 pounds. It feels like you're falling through the sky. The deeper I go the faster I fall (to a point).

So now I take a deep breath off of a regulator and all the sudden I go from - 4 lbs, to + 2 lbs. In a single breath. This would be the equivalent of dropping 6 pounds of weight when scuba diving.

So to the people that disagree with me, you are basically saying 6 pounds of lead makes a small difference for a scuba diver. It is nonsense, it is speculation from those that have not done it. I have. Now if you think I am here lying just lie then go ahead and continue to disagree with me.

But if you want to live in reality, then you know dropping 6 pounds of weight will cause you to go up, unless you fight it. I never said you will uncontrollably ascend like a maniac, but your free dive is over. You are not going to be able to maintain your depth without some type of assistance by the diver, or by holding on to something.

This is just a fact.

 

[Mark IV]

Actually, I do have a bit of experience here. I was a full time instructor and cave diver all over the Yucatan for many years, and have done a little free-diving (as well as being a spotter/safety diver for a freind that used to freedive below 100' ), and I've taken breaths from a divers tank, at depth, and don't recall acquiring any insurmountable degree of positive buoyancy. And, I've had to give lead weights to under-weighted divers, up to and including my entire weight belt, and I still managed to finish the dive and safety stop without great difficulty.

 

[IncreaseMyT]

Now let's take that a step further. You breath hold, dive down, take a full breath off a reg, AND drop your weight.

Thats what happens when you take your BCD off at depth and you have BCD integrated weight system, your corking.

 

[IncreaseMyT]

And, I've had to give lead weights to under-weighted divers, up to and including my entire weight belt, and I still managed to finish the dive and safety stop without great difficulty.

I had a feeling you would say that, because people keep trying to take what I say out of context. If your handing 5 lbs of lead to other divers, like a lot of instructors do on scuba. You are way overweighted and you use your BCD to compensate for it. Like comparing apples to oranges, obviously I was referring to a properly weighted scuba diver.

If you free dived and took a breath off a reg and "didn't notice an insurmountable change" then you were at 25 ft. Not 60.

 

[drk5036]

Here is the thing though, it is not a small change. Let me explain to you what happens when you free dive so that this makes more sense.

The first thing you wanna do when you free dive is adjust your weight. You will want to put on enough weight so that with a full breath you are still positively buoyant, basically you want your chin to touch the water in a vertical position. For me in salt water this is about 8 pounds, if I let out out breath, I will sink. I would guess I am 2 pounds or so positively buoyant (maybe more though).

So now I have got my weight on, and I am doing my breathe up. I take a deep breath and duck dive, swimming down the line. As I pass about 17 ft I start to become negatively buoyant. The deeper I go, the more negatively buoyant I become. Once you pass 60 feet you could be as negative as 4-5 pounds. It feels like you're falling through the sky. The deeper I go the faster I fall (to a point).

So now I take a deep breath off of a regulator and all the sudden I go from - 4 lbs, to + 2 lbs. In a single breath. This would be the equivalent of dropping 6 pounds of weight when scuba diving.

So to the people that disagree with me, you are basically saying 6 pounds of lead makes a small difference for a scuba diver. It is nonsense, it is speculation from those that have not done it. I have. Now if you think I am here lying just lie then go ahead and continue to disagree with me.

But if you want to live in reality, then you know dropping 6 pounds of weight will cause you to go up, unless you fight it. I never said you will uncontrollably ascend like a maniac, but your free dive is over. You are not going to be able to maintain your depth without some type of assistance by the diver, or by holding on to something.

This is just a fact.

It’s not the equivalent of dropping 6 pounds of weight at depth. It’s like being 4 pounds negative (you’re slowly dropping) then taking a full breath off your regulator, which makes you then 2 pounds positive. You’ll slowly stop dropping, then slowly start rising. Swimming against 2 lbs is easy; you already did it to get off the surface!