Please sir 'more air'

[KimH]

<font color='#000080'>Easy guys, Scubadog's only done a few dives, isn't some of this a bit OTT we don't want to put anyone off asking serious questions - I almost lost the plot there for a while.

Scubadog - don't rush things, take some time to enjoy your diving and don't try and run before you can walk - or whatever the wet equivalent is.  You shouldn't be too concerned about depths and times at this stage apart from where they impact on safety - I notice from a previous post that you say you qualified to OW in July so by rights you shouldn't really be thinking of going this deep just now, especially with another novice buddy. Take a while using the same kit configuration to see how you improve on consumption before you make any changes.  

Often it's counter productive to move onto bigger cylinders as the extra weight and effort increases consumption.  You may find that given a few more dives you'll relax more and a single 12 will be enough for the diving you're doing and you can also see how your buddy gets on as well.  Normally the fair sex do better on air than we do.

All the best and if in doubt don't be afraid to ask.

[scubadog]

just a little ditti to say thanks to all that have replied...and comments on saftey have been noted. &nbsp;One thing I have learned whilst reading notes posted on this forum, It is best to put as much back ground info in from the start, which I failed to do. So just to cap it off.
I wasn't diving with my partner, and as yet with haven't dived a on our own. We both agreed that we would gain experiance with other divers before we do that. And I personelly don't agree with any agency policy that gives people the oppotunity to go diving after getting wet only four times during their OW course.
The dive mentioned was made up of the following.....an instructor who also has several years experiance feeding sharks on guided dives, a Divemaster who had been a commercial diver, a diver of 40 years experiance as a commercial diver/instructor. And some bloke from Belgium who had over 200 logged dives. I know this doesn't excuse the fact that I went below the recommended depth for an open water diver, but unless such experianced divers where to hand I wouldn't have gone.

Scubadog......

[DIVE BUDDHA]

hi ya !! just like to add my opinion to this thread when i first started diving i was guzzling air now 50 dives down the line i can honestly say my air intake has been cut by approx 25-30% recently on a multilevel dive. i got out of a 15 litre tank at 232 bar a 58 min dive starting at 33 metres for approx 7 minutes then up to 20 metres for approx 20 minutes and all the rest was at 6 metres so no need to do a stop because i had been there so long looking at all the fish mmmm nice &nbsp;

[Simon A]

Scubadog,
If you are seriously guzzling air you may also want to check your weighting. I like you am a relatively novice diver (17 dives OW qualified) and I have found that if I am correctly weighted I come up with 25 Bar more than my wife, however if I am 1Kg over weighted I come up with 20 Bar less than her!
If anyone can explain how 1kg of lead can affect my air consumption so much I'd be interested to know.

Simon A

-----Edited for spelling -----

[daz]

I can think of a few reasons. &nbsp;

1kg overweight, equals more air to maintain neutral, and probably even more relevent, potentially worse trim in the water and thus more drag.

Does seem quite a difference though, but hey if it makes the difference than can't argue with the facts.

Daz

[Rupert Bear]

Newbies tend to get overweighted on their first dives. Because there is so much air in the suit it then becomes harder to maintain neutral bouyancy because the large volume air expands rapidly to small depth changes. The Newbie learns the easiest way to cope with this is to be slightly negative and in consequence have to constantly fin upwards to stay at the right depth.
&nbsp;This is one of the reasons air consumption goes up with extra weight, the other one being the extra air used in the suit in the first place.
&nbsp;You can see this with new or newly trained (or badly trained experienced) divers at most places just by looking around and watching the ones who swim like sharks and have to fin all the time!

[Simon A]

Rupert,
When I did my OW the instructor was insistant that we &nbsp;used as little weight as possible even to the extent of telling us that if we were light on th 5M safety stop he'd hand us some weight back.
He managed to get me down to diving 7KG in a 3/4 suit in the Red Sea (and I'm not a small person!)

The 1Kg overweight incident was when I'd just bought my own gear and was doing some shallow shakedown dives to get the weighting/kit config right, and yes I was an inexperienced diver (dives 8 and 9, but I got the weight right for dive 10).

Simon A