Dangerous lies?

[boulderjohn]

first dive is your deepest (sounds like a cat stevens song?)...

You will still hear this often, and almost all dive operations work on that theory. A workshop on that theory determined that the first occurrence of this was a suggestion without any explanation in a 1972 PADI manual. PADI was a member of the workshop, and it had no record of who made the original suggestion or what the reasoning for it was. It was repeated in subsequent manuals with increasing fervor until it became a rule. It is still written as a rule on the PADI RDP.

Everyone assumes there is a safety reason for it, but in all likelihood (admittedly just an educated guess) the real reason is very practical and MADE (not makes) a lot of sense. In 1972 everyone used the Navy tables for diving, and the big problem for that with recreational diving was the very, very long required surface intervals. If you go to the tables and put in two successive dives to different depths, you will see that the required surface interval is MUCH shorter if you do the deeper dive first. That is true of all tables, even the more modern ones with the shorter required surface intervals.

 

[Kenji]

If you get scared just press the red button on your BC and you'll go right to the surface.

I was on a boat where there was a group doing a LTS course and this was basically what the DM/Instrucctor said to them.
He also noted that at the end of the drive, " Inflate your BC and it will carry you to the surface like an elevator".

 

[boulderjohn]

Last year my guide in the Philippines stated deep stops reduced the risk of DCI.

This is still a very common belief. I don't believe it, but there are even some agencies that teach it.

Whats with the Mask on Forehead business? I was taught by all of my instructors that MOF is a signal of a distressed diver on the surface. Is this not accurate?

As Wookie said, equipment rejection, including the mask, is a SIGN of a distressed diver. A sign is something you observe in someone else. You can use it as a SIGN of a distressed diver when accompanied by other signs. If a diver is casually chatting with his buddy with the mask on the forehead while awaiting his turn to board the boat, the lack of accompanying panic signs indicates there is nothing to worry about.

In contrast, a SIGNAL is a deliberate act by someone with the intention of communication a message, such as putting your fist on your head to indicate that you are OK. A person who is in a panic is not going to place the mask carefully on the forehead as a means of communicating that panic.

 

[Lead_carrier]

There are so many untruths floating around that it will make your head swim. Probably the worst is, if you don't certify with "$$$" agency then you're not a real diver or if you don't use a backplate and wing you'll never be able to dive correctly. I'm sure that most anyone that's been around diving more than a few months have heard so many it's funny.

 

[boulderjohn]

I've often heard that you can't have both added safety and increased dive time with nitrox.

That silliness has been promoted regularly and emphatically by Alex Brylske in the pages of Dive Training magazine. That magazine is given out for free to students in dive shops all over the place. there must be many thousands of people who think he knows what he is talking about and therefore believe him.

 

[Bob DBF]

Having seen any number of panicked divers, I can tell you that the first thing they do is get rid of the mask (by shoving it up on their forehead) and regulator.

Anyone who says that a mask on forehead ISN'T a sign of panic is lying.

All a matter of context, I keep an eye on on divers MOF until I see whether they are having an issue or are getting ready for a bulls**t session with their buddy on the surface. I wouldn't assume one way or another.

Rejection of equipment is a sign of distress, the question is whether the diver is rejecting the gear or rearranging it for convience.

My avatar is a pic of me, MOF, on my way to the water and not in any distress. Since I went to a bungeed backup, I can't put my mask under my chin, so it is MOF instead.



Bob

 

[tilikum]

We can restart the MOF thread and all it's variations. I bet we can break the old record!

 

[nolatom]

Well, air's "safer" since less ox-tox risk if you go deep compared to nitrox.
But nitrox, within its Max depth limit, is sort of safer in that there's less narcosis risk, huh? Aren't we, at say 125' on N-28, less of a narc risk than on air?

But referring to the topic, I was taught in Nitrox class what the trade-offs were.

And what's "safer" when your limiting factor (say for a new diver) is gas consumption, may be a different world than later on when your gas lasts longer so that Nitrogen absorption becomes the limiting factor.

 

[stuartv]

Having seen any number of panicked divers, I can tell you that the first thing they do is get rid of the mask (by shoving it up on their forehead) and regulator.

Anyone who says that a mask on forehead ISN'T a sign of panic is lying.

I've had my MOF many times, while in the water, before and after dives. So far, it has never been a sign of panic. I am not lying. Usually it is simply a sign that i want to speak normally.

This is still a very common belief. I don't believe it, but there are even some agencies that teach it.

As Wookie said, equipment rejection, including the mask, is a SIGN of a distressed diver.

You are implying that MOF IS equipment rejection and, therefore, IS a sign of a distressed diver. Your wording is a little vague in this regard. Wouldn't it be more correct to say that MOF MAY represent equipment rejection and therefore MAY be a sign of a distressed diver?

 

[rhwestfall]

I'm frequently hearing that a BP/W is ONLY for technical divers.....