New Divers -- I need your help...

[Peter Guy]

I'm a DM candidate and want to pass along some "Gas Management" information for Dive Planning to my "students." Towards that end I've put together a very SIMPLE (I think) one pager which attempts to outline the most basic of basic ideas regarding "Gas Management."

I want new divers, especially ones who have just finished OW or AOW to take a look at the page and then let me know if it gives you any useful information -- or is it just confusing.

How Much Gas Do You Need For Your Dive?

How Much Gas Do You Need For Your Dive? -- REVISED version 2

Thanks for your help.

Of course, if you AREN'T a new diver, feel free to comment as well.

 

[jbmooney]

Peter, I can't get the pdf to load...

 

[Peter Guy]

jb -- don't know what to say because I've loaded it from three different computers and using both Firefox and EI. It did take a few seconds for the server to respond.

Please give it a try again.

 

[scubadale]

Peter, I can't get the pdf to load...

It was really slow for me using Firefox.

Peter, I just glanced over it so I can't really comment right now. Let's let some noob see it first and then I will chime in.

 

[Blackwood]

I'd like to see more discussion about "min gas."

I'd suggest adding it as a bullet point to your 5 pieces of information needed. I'd put it in as 3 (since it depends only on depth, not time at depth) and shift the rest down.

I'd also suggest calling it something else, like emergency gas or ascent gas (... or bingo or rock bottom). Even given your definition, I think calling it minimum is a potential source of confusion.

Also, since you don't spell out how to compute min gas, I think it may be beneficial to say something like: if diving to 60' or shallower, reserve at least 25ft³, if diving between 60' and 100', reserve at least 40ft³. That way they'll always be on the conservative side. Alternately, briefly discuss average depth and time of ascent such that they can easily compute min gas for their planned maximum depth.

 

[DivingPrincessE]

the link worked just find for me. I found it pretty darn confusing...but I hate numbers and math, and I don't think I'm anywhere close to being ready to dive in my own in the ocean. I paid extra in FL to have a DM as my buddy.

I find all the "dive planning" stuff very confusing. I get NDL, but unless you are familiar with the area...how do you know how deep you are going to be?? I never really worry too much about air consumption because I dive with guys and they always run low on air before I do...and I check my air like crazy.

 

[Blackwood]

I never really worry too much about air consumption because I dive with guys and they always run low on air before I do...and I check my air like crazy.

That's a very good reason TO worry about it.

If YOU have an emergency that cuts off your gas supply, chances are THEY won't have enough left to get you up.

 

[petronius]

As a new diver, I would find this useful (in fact, if you don't mind, I'll keep a copy). However, I have a couple of suggestions:

First, if you leave the table at the top, indicate that some of the terms (e.g. tank factor) are explained in the notes.

Second, steps 2 and 4 in "Information needed" could use more explanation/detail for us clueless newbies.

Finally, I would pull out the 60' example from the steps - give steps 1 to 5 in general terms, showing equations, and then provide the 60' example separately...

This is a good idea; I would have liked more discussion of 'min gas' in my OW class.

 

[RJP]

I'm a DM candidate and want to pass along some "Gas Management" information for Dive Planning to my "students." Towards that end I've put together a very SIMPLE (I think) one pager which attempts to outline the most basic of basic ideas regarding "Gas Management."

Of course, if you AREN'T a new diver, feel free to comment as well.

I think you need to ask yourself what kind of "students" you'll be passing this on to, and when?

I'm not saying this is the right way to think about it, but the topic in general and the "rock bottom" approach specifically, is so far beyond the comprehension of most recreational divers (especially) new ones, that I'm pretty sure that for every 10 student divers you "share" the information with 9 of them would potentially give up diving forever right on the spot if they thought it was gonna be that much work.

Think of your role as a DM related to assisting with "students" - ie supporting and helping the instructor. Of course your relationship with the instructor and understanding of what they want to emphasize will guide you, but I would be pretty put off as an instructor (not that I am one, but hypothetically) if while I was trying to make sure everyone had their BCDs on correctly and was trying to keep them off the bottom or from shooting to the surface your were going over "dissimilar tank volume calculations" and the like with them on the surface interval.

Again, you're addressing a very important concept but I think you should consider when, where, and with whom to "share" this information. People can only absorb just so much information at one time, and while I'm as vehement a supporter as anyone of making sure every diver is as safe as can be, early on it's most important to ensure that the students "enjoy safe diving" as opposed to giving them them the impression that "safe diving is hard work."

 

[jbd]

I find all the "dive planning" stuff very confusing. I get NDL, but unless you are familiar with the area...how do you know how deep you are going to be??

You do some research on the area you are going to be diving, before you make the trip. In some cases you may also need to set limits for yourself when diving some areas. For example many operators offer trips that involve wall dives. Sometimes the depth can be limited but in many cases the actual hard bottom is several hundred feet if not over a thousand feet. In either case you have to know what limits you have personally. Maybe you have never been deeper than 45 feet while diving many of the fabulous reef systems and now there is a wall dive with essentially no hard bottom. Do you automatically go to 130 feet because the rules say you can???? Or do you make the dive to 60 feet or 70 feet. Its your call, so thats the plan you make.

Another "wrinkle" you can run into is one that occurred on a recent trip I took. We were frequently told that bottom was at 60 or 65 feet. We enter the water, descend to the bottom; check the depth gauge and find the bottom is really 85 to 90 feet. This will change your plan Knowledge of the NDL's will help you deal with this on the fly so to speak, and of course many computer will make this info known if you pay attention to your computer.

I also agree with Blackwoods comments in post #7 of this thread.