8 changes...

[kmarks]

Not nearly as easily.

If your valve is closed all the way, you can't go more than one breath without noticing. You'll feel it right away and be forced to fix it right away, still on the surface, before descending. Just so long as you're not badly overweighted with a deflated BC.

If it's only open a quarter turn, things feel normal till you're on your reserve air - and then you can't breathe, with up to a hundred feet above your head and plenty of pressure on your gauge.

Sure, not nearly as easily, but a lot of vacation divers I've been on the boat with hardly know what they're doing. Especially on valet boats that do everything for you. I had to book a trip through Carnival at AKR in Roatan a few years ago and it was miserable - divers were all over the place, one guy switched his fins to his hands halfway through the dive, my buddy disappeared and ended up with the wrong divemaster... it was so bad that the DM just assumed everybody was an idiot and "helpfully" unclipped my fin for me as I was (the last person) getting back on the boat, and had just unclipped the other side, causing me to lose a strap. Yeah, anybody paying attention should notice that their tank is closed, but I wouldn't be surprised if one of these divers didn't until they hit the water with an empty BC.

I know which way is left and which way is right. To be clear, I'm not suggesting that instructors need to tell students to turn back 1/4 turn. I was told not to, but also told that it doesn't make a difference either way as long as you open the tank. I just do it because, like I said, old habits die hard. In the link, he suggests that if your acetylene tank leaks because you opened it too hard, you don't get to weld. As a chemist, I work with pressurized tanks containing anything from "inert" argon to HCl or Ammonia. Believe me, even in your hood, if those latter two lose a valve and leak, you're gonna have a bad day. Even argon, if it's bad enough, can displace oxygen in the room.

And before anybody thinks I had terrible instructors, they were all great, except one who just couldn't adapt to some people's learning style and kept yelling at my wife. My OW checkout, there were 10 students, 4 instructors, 2 divemasters, and a divemaster candidate. They watched us like hawks. (Hawksbill turtles?) We trained in a quarry where you couldn't see anything but green blobs and it was 57 degrees. My first night dive in Cozumel was a cakewalk.

I've never taken off my gear while underwater since training. But that quarry I mentioned? Full of fishing line and other entanglement hazards. I wouldn't dive it without two cutting devices and the ability to squirm out of my BC if necessary. I've seen DMs in Cozumel pop the gear off and back on again while hunting lion fish. Having a neutrally buoyant BC/tank/reg and being weighted on the body makes this easy.

 

[Blasto]

Sure, not nearly as easily, but a lot of vacation divers I've been on the boat with hardly know what they're doing.

But there's one thing we all know and do: breathe. If your valve is closed, you can't do it, and that's hard not to notice.

If you're on a cattle boat, doing full open makes ensuring safety procedure much easier. You just need one person who knows left from right to guard water entry. Open every valve, don't let divers jump in unless they've got their reg in, mask on, BCD inflated, no one below, two breaths before the jump.

 

[The Chairman]

How do you distribute weight between rig and weightbelt (if using any) for your students?

This past week I had my very first weightbelted student in a long, long time. Her waist was soooooo tiny, that the pockets wouldn't work on her.

However, that simply made the BCD assembly neutral, and her as well. She did the skills in the exact same way. It was beautiful.

 

[The Chairman]

But there's one thing we all know and do: breathe.

Indeed. Listen for your buddy breathing their rig during kit up. If you didn't hear them, kindly ask them to take three breaths for you before you splash.

 

[kmarks]

If you're on a cattle boat, doing full open makes ensuring safety procedure much easier. You just need one person who knows left from right to guard water entry. Open every valve, don't let divers jump in unless they've got their reg in, mask on, BCD inflated, no one below, two breaths before the jump.

I'm not disagreeing with this. I'm just disagreeing that the diver he mentions died because he turned his tank back a quarter turn. He didn't. He died because he turned his tank ON a quarter turn.

 

[Kharon]

What’s a weight belt?

It's something I use (sans weight) to hold up my jeans. Perfect width, can be set at any waist size, and never wears out. Plus, if you have an emergency it's easy to drop your trowsers.

As far as a snorkel: first, I snorkeled far longer than I have been diving and still do; second, I sometimes do long surface swims and see no reason to waste gas; third, I see no reason to not look down into the water column if I'm on the surface waiting; fourth, the snorkle impeads me in no discernable way; and finally, if I want to have a snorkle attached to my mask, who the eff is the author to say I can't. And I will put my mask on my forehead, thank you very much. Dive and let dive - and make no judgement.

 

[Blasto]

Yes. It's always mistakes that kill.
The debate here is about which mistake is more dangerous: full off or quarter-on. Both are equally probable within their respective protocols.

Full off has high detectability and either low or high impact depending on whether the BC is inflated. Quarter-on has low detectability and medium to high impact depending on dive depth.
The impact of either can be mitigated to low by skill: for quarter-on, by underwater doff-don, for full off, by either weight release or just underwater doff.

 

[TONY CHANEY]

Yes. It's always mistakes that kill.
The debate here is about which mistake is more dangerous: full off or quarter-on. Both are equally probable within their respective protocols.

Full off has high detectability and either low or high impact depending on whether the BC is inflated. Quarter-on has low detectability and medium to high impact depending on dive depth.
The impact of either can be mitigated to low by skill: for quarter-on, by underwater doff-don, for full off, by either weight release or just underwater doff.

You do realize that we are talking about the tank valve being full on or full off or full on and then backed offed a 1/4 of a turn?

 

[TMHeimer]

I haven't read the posts. My thoughts:
--Quarter turn on valve. No need to do this, as proven. I still do out of habit. Pretty hard to kill yourself, unless usted tiene no sesos.
--weights. Teach both integrated and belt removal. I can't see how I wouldn't need a belt diving in 7 mil farmer john carrying (yes....) 42 pounds. Our shop teaches both.
--"dorkel. Sometimes I carry a foldable one in the BC pocket--depending on situation. Haven't use it yet. Depends on type of diving you so and possibility of current pulling you somewhere that you have to swim like, miles. I know---you can swim on your back and not need a snorkel and also have to turn your neck to see where you're going. Don't think we want to get into all of that sh!t.

 

[tomfcrist]

I can't see how I wouldn't need a belt diving in 7 mil farmer john carrying (yes....) 42 pounds.

42 lbs? If I ever had to choose between 42 lbs of ditchable weight and a sex change operation...you could just go ahead and call me Crystal.