Dialing in Skills

[Red_October]

Hello,

Just finished my PADI AOW/Nitrox. Still having a blast diving but really want to enjoy it for a bit instead of throwing more money at c-cards. That being said, I still want to improve my diving. Does anyone have any write-ups/reading materials on the finer points of skills like breathing, buoyancy control or trim? On my last three AOW dives I was pretty proud of myself for completing all the dives on one 12L tank of Nitrox with over 50 bar left. Sure they were short ~40 minute dives at shallow depth, but the water was a balmy 55º and the other student had to turn his cylinder after every dive. I'm sure it was no stellar SAC rate, but it was a marked improvement for me. But, I didn't know if I was breathing "right" or if I was doing something bad like skip breathing. Point is, I'd like to feel even more control in the underwater environment without Putting Another Dollar In.

On a related note, when I head back to the States we've got a pool thats ~15 ft deep. Is it the worst idea in the world to get some gear and practice those skills in such an accessible location or is the consensus that only open water conditions are worth diving in?

 

[Doc]

Read when you’re not diving.

Get wet. Your skills will improve most quickly when logging dives.

Pools are good to get comfortable in various positions. Close your eyes, think about buoyancy, try dozing off. Once you can do that, your SAC will become a non-issue.

 

[EFX]

Getting 120 minutes for three dives on one tank in shallow water, I think is good at least from a SAC POV. As long as you are not skip breathing I would be concerned with breathing too shallow. Your breathing under water should be slightly deeper and longer (slower) than breathing at the surface. This is to prevent CO2 retention which can lead to greater anxiety, breathlessness, light headedness, especially at greater depths and can lead to black outs in severe cases.

I would definitly work on getting your weight and trim right which will help with your buoyancy. There are many threads on SB besides your instruction manuals that discuss this.

 

[TMHeimer]

All good points. Pools are OK. Note the difference in buoyancy vs. salt water--a little harder to "hover", perhaps?
Also agree--read over your materials, ScubaBoard threads, and google videos on trim, kicking, buoyancy, etc. I think there are a lot more than when I started in 2005.

 

[PullYourselfTogetherMan]

Sounds like he wants to drink the kool aid, boys. I say he should

 

[Red_October]

I don’t meet the lifestyle requirements for doing it right

 

[Zef]

For breathing:

It is often abstract to interpret "breath normally" because most of us don't regularly/consistantly breath through our mouth above water especially in a relaxed state.

The info imparted on new divers is often "don't hold your breath" and the manual(s) briefly discuss the dangers of skip breathing.

Based on the above the new diver has a tendency to inhale and exhale constantly in fear of "holding their breath" or "skip breathing".

I offer that when we breath on land there, particularly in a relaxed (non-exertion) state, there is a natural pause between our inhalations and exhalations, this natural pause should be present when breathing off a regulator, with the caveat that you should be more aware of it when ascending and perhaps stop ascending or slow the ascent during that phase of the breathing cycle. This pause is not the same as "holding ones breath" as the air should be able to pass freely if it expands, where as when holding one's breath one is actively retaining the air and it has no place to go which is very risky.

Breathe as necessary....just because you took a breath in or exhaled does not mean you have to take the reverse action right away...your lungs do not always need to be full or empty, in a state of one end of the cycle or the other. Just like when you are sitting at a computer you can breath in and your body will process the gas and eventually your CO2 level will rise enough to stimulate a "natural" exhalation...of course if your lungs are full be aware if you are rising or falling in the water column, but it is generally ok to have the gas in your lungs allowing your body to utilize it...the same is true with exhalation...there is still residual air/O2 in your lungs so there may be a natural pause at the end of an exhalation as well.

These natural pauses are one key way that our SAC rates improve.

So what is the difference between these natural pauses and skip breathing?...

....Skip breathing is the intentional avoidance of exhaling in an effort to try and maximize ones air/gas supply. The problem with this is that the primary driver for breathing is typically not the need for air/O2 but to evacuate CO2. When one "skip breathes" they cause the body to build up CO2 which can lead to problems such as hyperventilation, shallow water blackout, or lung over expansion injuries as skip breathing is often accompanied by breath holding.

Unless swimming into a current, or purposely working underwater (i.e. salvage work, hunting/spear fishing, etc.), it is often considered a best practice to try and maintain a relaxed state. Get lost in the breathing cycle and just enjoy being underwater. Be more aware of the pause between inhalation-exhalation and exhalation-inhalation the closer you get to the surface.

The biggest impact on your ability to use the gas in your cylinder more efficiently will be time spent underwater. The more time you spend in the water and the more experience you gain the more relaxed and confident you will tend to be and therefore your breathing will naturally slow down and your cylinder should last longer.

Hope this helps.

-Z

 

[Griffo]

I don’t meet the lifestyle requirements for doing it right

What are they?

But seriously. Find an instructor or diver who looks good underwater and dive with them.

 

[Zef]

On a related note, when I head back to the States we've got a pool thats ~15 ft deep. Is it the worst idea in the world to get some gear and practice those skills in such an accessible location or is the consensus that only open water conditions are worth diving in?

This is a great idea. I belong to 2 clubs, one has exclusive use of a pool nearly every Wednesday evening and the other nearly every Thursday evening. Other than students who are in formal classes, there are folks who practice apnea, there are folks testing new gear, there are folks shaking the cobwebs off gear they pulled out the closet after months/years of non-use, and there are folks who are working on honing skills.

If you have a 15ft deep pool you should definitely use it to your advantage. Work on dialing your weigting, work on perfecting your weight placement to perfect your trim, work on establishing/improving your frog kick and reverse kick, work on launching a DSMB, work on all your basic scuba skill will hovering off the floor of the pool.

Mix things up from time to time and do some apea work...apnea exercises typically translate to increase comfort and confidence when diving on SCUBA.

Everything you do in the pool will benefit your diving in open water.

-Z

 

[Divectionist]

Search for some scuba related books, those on accident analysis/prevention (like 'Diver Down') and those discussing general diving skills (like 'Scuba Exceptional' etc).

I've read plenty of books on diving and the odd nugget sticks and can make a difference, particularly regarding accident prevention and problem identification.

The following do not classify as 'finer points' on breathing, trim and buoyancy, but I really think it is as simple as that:

As far as breathing goes - 7 seconds in, 1 second transition, 7 seconds out = 4 breaths a minute for any standard diving situation = great SAC rate. Don't sweat if you take 5 or 6 sometimes, or more if working harder. The key is to START inhaling slowly, i.e., not inhaling too quickly to crack the 2nd stage open. A good and well tuned reg make a big difference in achieving a natural and controlled slow inhale. If you are not frog kicking already, start doing that. Keep everything else still, be lazy. Stay warm through exposure gear. Breathing solved!

Trim you just have to get right by hovering motionless with good posture, and noting your position in the water, and observing any tendencies to roll, then counteract with your equipment (weight distribution, cam band weights, positioning of tank) until a motionless hover with the same good posture results in the desired trim. Bp/w or at least a rear inflate BCD helps also.

Buoyancy is just a matter of awareness and measured action. Start by getting your weighting spot on. Do your weight check with your cylinder at reserve pressure or add weight for the volume of air you'll breathe if that is not available to you. You got it right when you really need to really exhale and hold still to descend the first couple of metres. Don't be shy to adjust a lot until you find yourself adjusting less and less. Strive for an element of proactivity as you descend and ascend, soon you will intuitively inflate or dump just about the right amount.

You can play with this in the pool but unless you own your gear, your trim at least will vary every time you rent gear, and you won't be able to fine tune trim or even dive with spot on weight most times.