Frequency of advanced divers practicing CESAs ? [Poll]

[Diving Dubai]

Figuring out proper trim and weighting for cold salt water today, slightly warm fresh water tomorrow, and tropical conditions a week later is a little different. Throw in steel tanks at home and AL tanks on trips and things start to become complicated

I'm not sure I understand?

I may be in a wing with a steel or my BCD with and ALi, I go from rash vest to Drysuit, have AL80 aor AL 40 as slings or none, in any combination. While my weighting changes for exposure and tanks, the placement does not (except when I teach OW when I have a little on a weight belt for demo)

IMO Trim should be about body position maintained by body movement (core muscles) not by weight placement - unless you have really floaty legs in a DS

 

[markmud]

I'm not sure I understand?

I may be in a wing with a steel or my BCD with and ALi, I go from rash vest to Drysuit, have AL80 aor AL 40 as slings or none, in any combination. While my weighting changes for exposure and tanks, the placement does not (except when I teach OW when I have a little on a weight belt for demo)

IMO Trim should be about body position maintained by body movement (core muscles) not by weight placement - unless you have really floaty legs in a DS

Hi DD,

I go from a 1/2 mill wetsuit to 10 mils on my body with 5 mils on my legs with other combinations in between. I tend to be a little "floaty" in the core with 10 mils of rubber on my torso. I have gone from 48 degree water to 85 degree water in a matter of weeks. I mean 48 degrees at the surface.

Also, I tend to be a little OCD, so I do trim-out to an extreme. A pro, like you, probably works-through minor trim issues that would bother me (no pun or sarcasm intended in this sentence--you are a pro and I am not).

cheers,
markm

 

[Kharon]

IMO Trim should be about body position maintained by body movement (core muscles) not by weight placement - unless you have really floaty legs in a DS

That only works if your center of gravity is at the center of your body. Mine is not naturally. I'm very leg heavy. Therefore I need to distribute weight to accomplish moving the center of gravity there. In fresh cold water I've got insulation that moves my center up because my legs are buoyed somewhat. In salt water with no insulation my legs are heavy and that moves my center down.

The weight is in the same places, the distribution is different fresh & salt. And like markmud, being a bit OCD, and wanting to be able to hover in any position that a trumpet fish can, I made weights in half pound increments. Depending on how I sling my pony, the distribution can vary from side to side as well as top to bottom.

 

[Diving Dubai]

Also, I tend to be a little OCD, so I do trim-out to an extreme.

And like markmud, being a bit OCD, and wanting to be able to hover in any position that a trumpet fish can

Valid points by both of you gentlemen.

With out being condescending nor critical, if I may offer an option for consideration.

I too am OCD about trim and position, and I pride myself in my ability to blue water hover with little deviation. I used to be incredibly particular with getting my weighing precise.

Now with weighting I'm not so bothered. Often while divign with new diver's I will be significantly overweight, so I have additional weights on hand, and also so that I have teh ability to arrest a divers ascent purely by holding them and dumping my air. Similarly (whilst over-weighted) there have been a few occasions where I've had to manage the ascent without being able to dump my air because my hands are full. Yet in all of these situation my ability for control of buoyancy and position isn't' compromised.

The technique for this (not that I suggest you dive overweight) is to fully control your breathing. You'll be surprised at how much compensation they give you.

I also take the point regarding a slung cylinder. Certainly with an Al80 slung to one side, and to a lesser extent with an AL40, if I become motionless and relax I will ge a slight rotation due to the offset weight. In practice this is never an issue because this rotation is easily countered with a bit of body counter force - a bit like riding a bicycle.

My point here is, although getting your weighting as close to ideal is recommended, being a little over (or under) is easily compensated for by just using our bodies natural abilities

Safe diving

 

[markmud]

Valid points by both of you gentlemen.

With out being condescending nor critical, if I may offer an option for consideration.

I too am OCD about trim and position, and I pride myself in my ability to blue water hover with little deviation. I used to be incredibly particular with getting my weighing precise.

Now with weighting I'm not so bothered. Often while divign with new diver's I will be significantly overweight, so I have additional weights on hand, and also so that I have teh ability to arrest a divers ascent purely by holding them and dumping my air. Similarly (whilst over-weighted) there have been a few occasions where I've had to manage the ascent without being able to dump my air because my hands are full. Yet in all of these situation my ability for control of buoyancy and position isn't' compromised.

The technique for this (not that I suggest you dive overweight) is to fully control your breathing. You'll be surprised at how much compensation they give you.

I also take the point regarding a slung cylinder. Certainly with an Al80 slung to one side, and to a lesser extent with an AL40, if I become motionless and relax I will ge a slight rotation due to the offset weight. In practice this is never an issue because this rotation is easily countered with a bit of body counter force - a bit like riding a bicycle.

My point here is, although getting your weighting as close to ideal is recommended, being a little over (or under) is easily compensated for by just using our bodies natural abilities

Safe diving

Hi DD,

I understand what you are writing about. I do extra cross training before a dive adventure to ensure that my lungs and major muscle groups are in reasonable condition. Good cardiovascular health means that I have not used my BC in the last 20 dives or so. I don't need my BC when I am trim, weighted properly, and have good vital capacity. Controlling your breathing makes diving neutral so easy.

And, I don't use much gas.

I am just a glorified vacation diver. I don't advertise any expertise other than to take care of myself, my buddy and no one else. I leave that to the professionals. I avoid diving with poor divers and unsupervised newbs. I can dive without extra weight or vigilance because I dive for me--you are in a completely different boat. Selfish...yeah...I have been called that before.


I appreciate the comms between Kharon, you, and me.

cheers,
markm

 

[markmud]

That only works if your center of gravity is at the center of your body. Mine is not naturally. I'm very leg heavy. Therefore I need to distribute weight to accomplish moving the center of gravity there. In fresh cold water I've got insulation that moves my center up because my legs are buoyed somewhat. In salt water with no insulation my legs are heavy and that moves my center down.

The weight is in the same places, the distribution is different fresh & salt. And like markmud, being a bit OCD, and wanting to be able to hover in any position that a trumpet fish can, I made weights in half pound increments. Depending on how I sling my pony, the distribution can vary from side to side as well as top to bottom.

Hi Kharon,

+1. You nailed it. I would probably enjoy diving with you.

markm

 

[yle]

No, it does not tell you how long it will last, because when you are ascending, the gas in your lungs is expanding. At 100 feet, you have 4 times as much gas in your lungs as you would when you do when practicing on the surface.

I met two people who had to do emergency CESA's, one from 75 feet and one from 100 feet. Both said that one they started exhaling, the air started coming out faster than they intended, and it was still coming out that fast when they reached the surface.

Hmmm... thank you for the OW Day 1 lesson: the air in our lungs expands as we ascend.

My apologies, I misspoke in my original post. Exhaling at a constant depth would give you a very conservative idea of how long a breath could last if you were ascending. So exhaling that one breath will always take more time (assuming a controlled rate of exhale, which was the entire point of my post...) while ascending than while at a constant depth.

The point of my post was that we don't actually have to ascend during a dive (who wants to do that?) to practice the skills necessary for performing a CESA, should the need arise. If I can exhale one breath for 60 seconds while at a depth of 60 feet, then I know I can easily CESA from 60 feet (because while ascending that breath will take even more time to exhale) if I ascend at 60 ft/min.

 

[KenGordon]

Hi Pete,

I agree with Kharon, for the most part.

As I read Kharon's post he is talking about having a matrix for vastly different diving conditions and gear. I have the same problem. To have good trim and weighting with all of the different configurations of wet suit and tanks, I too created an excel matrix to keep track of the different trim and weight placement scenarios.

As you have stated, being taught proper trim, weighting, and swimming attitude (horizontal verses vertical, or angled) is critical and not that difficult.

Figuring out proper trim and weighting for cold salt water today, slightly warm fresh water tomorrow, and tropical conditions a week later is a little different. Throw in steel tanks at home and AL tanks on trips and things start to become complicated.

thanks,
markm

Sounds like you have too many choices.

I put weight on a weight belt. Maybe a v weight on a twinset. My only option is which fins to use, which comes down to one set for a twinset, one for everything else.

After that it is just a question of how much weight, which obviously varies with fresh vs salt and thinkness of suit or undersuit.

I think trim weights are evil, like ankle weights because they complicate matters while not really helping. In general people can get trimmed by force of will or moving their tank. People who have the skill don’t need weights in wierd places and can manage with whatever kit they happen to be using. Telling novices that they don’t need more skill/practice but need to figure out where to move lead to is adding to the complexity and a lot of ****ing about to little advantage.

 

[markmud]

Sounds like you have too many choices.

I put weight on a weight belt. Maybe a v weight on a twinset. My only option is which fins to use, which comes down to one set for a twinset, one for everything else.

After that it is just a question of how much weight, which obviously varies with fresh vs salt and thinkness of suit or undersuit.

I think trim weights are evil, like ankle weights because they complicate matters while not really helping. In general people can get trimmed by force of will or moving their tank. People who have the skill don’t need weights in wierd places and can manage with whatever kit they happen to be using. Telling novices that they don’t need more skill/practice but need to figure out where to move lead to is adding to the complexity and a lot of ****ing about to little advantage.

Hi Ken,

I am very happy for you!

So, when did you see me diving with ankle weights? When did you see me with my other trim weights?

I do use a trim weight in a trim pocket when I have my full custom wetsuit on (ten mills on my core, and 5 mils on my legs), other than that, no trim weights.

You are correct, adjusting your tank up and down your body is huge. The largest and heaviest mass that we dive with is our tank. I see divers with tanks bottoms at the knees and the divers wonder why they can't trim out...it is hilarious. And then, a PRO will tell them that tank position won't help the condition...again, it is hilarious.

This fin for that rig and that fin for a different rig is kind-of-like trimming out--isn't it?

Dive and let Dive...("I think you have too many choices").

I used to live in Commiefornia. We did have too many choices. We could dive cold water salt water one day. A semi warm Alpine lake the next day, drive to SoCal and be in sub-tropical water the third day. Yeah, we had too many choices.

cheers
markm

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[MichaelMc]

In general people can get trimmed by force of will or moving their tank.

'Trim by will', or trim by 'how' you tense your muscles, (not where you hold your body, but how you tense), I always find fascinating. I don't think gravity cares about either.

Heavy/light fins or moving the tank sound a lot like shifting lead for trim, without changing my propulsion tool, or the spot where I lose 6 lb. of air weight during the dive, assuming I did not have that center of air way below my center of volume to begin with. If you have no lead, you have to scull like a mo. fo., but if you do have lead, not putting it in the optimal place seems silly. But to each their own.