Steel back plate and wetsuit not a good idea for solo?

[captain]

Every object submerged in water no matter if it floats on the surface or sinks to the bottom is acted apon by the bouyant force. What would be a better discripton of an object that will sink rather than float. To my way of thinking negative bouyancy indicates that the bouyant force is less the the weight of the water displaced by the object and positive bouyancy bouyancy indicates that the bouyant force is greater than the weight of water displaced.

What would be a better discription of these two situations than negative and positive. If I am bouyant I float but what am I if I sink. I could say I am negative but that might be taken as having a negative outlook on life. What word best describes the opposite of bouyant. Maybe gravitationally positive

 

[b1gcountry]

Believe it or not, you also have a buoyant force when submerged in a gaseous mix of Nitrogen and Oxygen, although this only adds up to about .20lbs for the average person...

The three terms I like to use are Buoyant, Neutral, and Heavy. I've noticed that the students in an open water class have never questioned my use of these terms, although a few certified divers have corrected me when I said Heavy simply because they are used to hearing "Negatively Buoyant".

I wouldn't have as much of an issue with it except that it infers that you can control the amount of buoyant force acting upon you by adding lead, which really is not what you are doing. Once a diver understands that there are two forces pulling them in opposite directions, it is a pretty quick transition to understanding why they always roll on their backs when they are trying to hover in the water column.

 

[captain]

Once a diver understands that there are two forces pulling them in opposite directions, it is a pretty quick transition to understanding why they always roll on their backs when they are trying to hover in the water column.

Uh! Explain

 

[b1gcountry]

I spoke about a more specific case than I should have mentioned, but what I meant in general was that if you have something with a lot of mass, like a weightbelt, it will try to sink. Something with a lot of buoyancy like an air bladder or a thick wetsuit will want to float, so naturally the buoyant parts will try to put themselves on top of the heavy parts.

What I meant specifically was that a diver in a buoyant suit wearing a heavy tank: the tank will try to be on the bottom, flipping them on their backs while they try to do the "cross your legs and hover" skill in OW.

 

[captain]

More of a center of gravity issue than a bouyancy issue. A boat floats upright because it's center of gravity is below the surface of the water. A ball will float in any position be cause it's center of gravity is located at it's center,

 

[ArcticDiver]

Going back to the original post; why would a solo diver a)go into a possible entrapment situation? and b)choose to take their rig off thus adding to the forces they must control while extricating themself? Why not just avoid entanglement and if somehow stumbling on a fishing line, or somesuch, just cutting out of it?



By the way yes, I do use a SS BP and a Wetsuit with single and double AL tanks. Even then I need additional lead to get down; that I can dump at the surface if needed. No, I would not use SS BP with a Wetsuit and steel tanks. I can swim them up. But, to stay there I have to dump the entire rig. I'm too cheap to throw away all that money unless I have to.

 

[Darnold9999]

Going back to the original post; why would a solo diver a)go into a possible entrapment situation? and b)choose to take their rig off thus adding to the forces they must control while extricating themself? Why not just avoid entanglement and if somehow stumbling on a fishing line, or somesuch, just cutting out of it?

Diving anywhere where fishing is done is a possible entanglement situation. Can't think of too many dive sites around here where nobody ever fishes. There are a couple but diving those sites over and over gets old and even there line drifts in. You often can't see fishing line to avoid it. So that leaves not diving solo at all as the only option to your a) above.

Re b) If you get line wound around your 1st stage it can be much easier to get out of your gear, turn around and disentangle or cut your way free, than to attempt to reach back blindly and cut your way free. It may even be more than easier, it may be the only way you can get yourself free as waving your hand around trying to find the line behind your back may just get that hand wound up in line too. In that situation I want the difference in boyancy between me and my gear to be as low as possible so I am not a balloon on a string. Which is what happens if all your weight is on your backplate and you remove it - diving in cold water.

 

[ArcticDiver]

I'll give your comments some thought. So far everytime I've gotten entangled, not many, removing my gear was not a preferable choice over just cutting out with shears.

As I visualize it, the situation you pose is that the first stage is entangled and you can't see the line to grapple and cut out. So, you are concerned that a sweeping hand might be entangled too.

I wonder what the odds are that in the process of taking the gear off, or after it is off that something else gets entangled in the unseen line?

 

[donooo]

Peteranodon, the point being made at the legendary 'solo' class at Lake unPlesant was more about not having all of your weight on your weight integrate BC.( Like the equipment exchange in your DM/Dive Conn class.) At the lake the instructor had a harness on under his harness that held his weights. He could then remove his BP/W and stand a chance of staying down. Lots of people still dive this way, not nearly as expensive, but it is called a weightbelt.


adios don O