The 20 Skills Broken Down

[Joe-Diver]

lishen hasn't been here since July and hasn't posted in over a year, so I wouldn't hold my breath.....

 

[Kingpatzer]

4. Buoyancy Check at the Surface

• Regulator in mouth
• Deflate BC completely
• Hang vertical and motionless while holding a normal breath, if properly weighted you should float at eye level
• As a check, exhale. You should sink slowly
• Add or subtract weight until you float at eye level holding a normal breath

That is the way the skill is done. But I'm just dumbfounded as to why. PADI's horribly written and even more poorly edited Encyclopedia of Recreational Diving says on page 4-20 that when properly weighted you will float at eye level with a near empty cylinder.

Yet the skill is done in classes at the start of the dive with a full cylinder. If you know your cylinder's buoyancy characteristics, you can of course do it this way and then add appropriate weight (6# for an alum. 80cf), but that is not part of the standard.

*shrug*

 

[boulderjohn]

That is the way the skill is done. But I'm just dumbfounded as to why. PADI's horribly written and even more poorly edited Encyclopedia of Recreational Diving says on page 4-20 that when properly weighted you will float at eye level with a near empty cylinder.

Yet the skill is done in classes at the start of the dive with a full cylinder. If you know your cylinder's buoyancy characteristics, you can of course do it this way and then add appropriate weight (6# for an alum. 80cf), but that is not part of the standard.

*shrug*

While that is a good point, there is actually some dispute of that. There is a contingent who believe at the beginning of a dive, the diver has some hidden buoyancy characteristics that will vanish like magic during the dive. If the diver is wearing a wet suit, for example, it will compress at depth and it will not reach its original buoyancy until well after the diver has surfaced. There is trapped air in a number of places in the wet suit and BCD. Those who hold that point of view, and there are some quite veteran divers in that group, say that it works just fine as described at the beginning of the dive.

BTW, I am not sure where I stand on the issue myself.

 

[Kingpatzer]

I personally find it to be a failed methodology. I prefer to drop to 15' with 500 psi and hover with an empty BC. That gives me a (near) worst case scenerio for weighting -- I'm on a safety stop with a nearly empty tank and a bcd issue.

But that really isn't the point. The point is that in the Physics section of the Encyclopedia which is used as an instructional text in the DM course specifically states one way to do it. Yet in the pool sessions nearly every DM candidate will do the skill in a way that is contrary to the instructional material.

 

[Walter]

After 94 posts, I still don't know which 20 skills have been singled out. Did it ever get past 11?

 

[Kingpatzer]

In no particular order:

1. Pre-Dive safety check (BWARF)
2. Giant Stride Entry
3. 5-Point Descent
4. Mask Removal and Repelacement
5. Regulator Recovery
6. Breathing from a free-flowing regulator
7. fin pivot
8. hover
9. BCD removal and replacement underwater
10. weight belt removal and replacement underwater
11. BCD removal and replacement at the surface
12. Weight belt removal and replacement at the surface
13. CESA
14. 5-point ascent
15. underwater swim without a mask
16. buddy breathing stationary and swiming
17. snorkel-regulator exchange
18. clearing a flooded mask
19. Assemble and Dissassembling gear
20. Weight Check

 

[A34735]

Why does the weight-belt go on first? I learnt, a long time ago, to put it on last, so it would be on the outside. I think the idea was to ensure it could be released without hanging up on other gear.
And I still do but I've noticed others on the boat looking at me strangely. Am I hopelessly out of date and dangerous?

 

[boulderjohn]

Why does the weight-belt go on first? I learnt, a long time ago, to put it on last, so it would be on the outside. I think the idea was to ensure it could be released without hanging up on other gear.
And I still do but I've noticed others on the boat looking at me strangely. Am I hopelessly out of date and dangerous?

Outside of what?

The weight belt is usually worn on the hips, over your wet suit or dry suit. The BCD is independent of the weight belt. The weight belt buckle accessible, but much of the belt itself is indeed usually covered slightly by the BCD. The way it is usually configured, it really doesn't matter which one goes on first, because a few pulls and tugs later everything is in its proper place.

That being said, it is a lot easier to put the weight belt on first, so that is what most people do.

 

[Scott]

I'm betting A34735 meant the outside of the crotch strap. This was the standard practice with horse collar type BC's and I suspect it's still the case with any BC that has a crotch strap. The last thing you want is a belt getting hung up on the strap when trying to ditch it.

 

[Jim Lapenta]

Actually standard practice with a BPW and crotch strap is to wear the belt under the strap to prevent an accidental loss of the belt. You never want to drop weights at depth anyway. At least not all of them. On the surface it is not hard and takes maybe another second to undo the waist buckle and strap and ditch the belt. Of course if you are diving a balanced rig as you should, there is plenty of time to drop weights after you swim your rig up. I know of a few who wear the belt over the strap but that is not the norm. The idea is to allow the crotch strap to catch the belt in case of an accidental opening of the weight belt buckle. I do not have to remove the belt when using it with a BPW. I have XS weight pockets mounted upside down on a standard web belt. If I need to drop any weight all it takes is a pull on the velcro and I can drop as much OR as little as I want. Being that the most I ever use in a belt is 3 - 2lb weights or 2- 3's and a 2, I would rarely have to ditch more than one of those to be positive enough to make a safe ascent and stay on the surface. Worst case is it'd take a second to open the other pocket at the surface. Or ditch the entire rig. Usually though I carry no dumpable weight.