Why can't I dive twice on the same tank?

[bottlefish]

I think that member of your dive group needs to take a step down. Relying on one person, expecting one person to have all of your problem solutions up their sleeve can be dangerous in it self. What's the plan if it's you that had gas problems. Also, what if you weren't close enough to the problem to assist, had to bail early from the dive for whatever reason and so not even there etc.

Seasnake makes a valid point, we are all spare air carriers for each and every one of the other people we dive with, in case they have major problems with air supply and we're the ones that have to assist. So we should always have enough air left in our cylinder to get us and An Other to the surface safely in case of problems. Provided you have this, then obligation sorted... assuming you are running on a no deco schedule, then not too hard to manage.

[acelockco]

FYI,

On New Jersey Dive boats, MANY of the divers use doubles, and do two seperate dives on the same cylinders. I thought it was strange as well, but even on their second dive, they start off with more air than I have in my al80.

[seasnake]

FYI,

On New Jersey Dive boats, MANY of the divers use doubles, and do two seperate dives on the same cylinders. I thought it was strange as well, but even on their second dive, they start off with more air than I have in my al80.

I do that, but I think it's more out of laziness ... so I don't have to switch tanks between dives ...

[littleleemur]

Even if I use my tank twice, I still have enough for my buddy, and more. So I'm fuming about the fact that someone is suggesting that I have to carry all that air to literally be an air-wetnurse for a bunch of potential idiots. In that line of logic: how long is my safety stop supposed to be exactly? 1hr until everyone is out of the water?

As for the doubles: how do you get out of the water with all that weight?!

[bottlefish]

Hmm, re-educate, or find a new dive team :-)

Getting out of the water for doubles? Ah, well that sort of divings not for women really, they're too weak and fragile... OK, that was in bad taste (sorry!).

It does take a bit more care, but not as hard as you might imagine. Plus, if you're air is as good as you say, then there's no need for you to double on 12 litre cylinders, take a couple of tens or eights instead.

[littleleemur]

My air management is ok so I haven't really thought about it until now. I average about 2/3 -1/2 an 80 for all of my dives so far. I haven't taken any of those clinics or courses but I'd like to.

[acelockco]

Now I am confused?

It shoud be a rare time when you can reach your NDL on an AL80 and a non repetative dive. Is there something I am missing? Are you VERY VERY SMALL? Like 4'5" 70lbs?

What is your avg. dive depth and bottom time? I am just trying to figure this out.

[allisonfinch]

[QUOTE=bottlefish;8924]Hmm, re-educate, or find a new dive team :-)

Getting out of the water for doubles? Ah, well that sort of divings not for women really, they're too weak and fragile... OK, that was in bad taste (sorry!).

Whew! I don't trust myself to reply to this!

I always get a chuckle when I see guys show up on a strictly rec dive with doubles. I use them for tec dives but don't feel the need to try to impress the reccies when they are not necessary. I think it's a waste of energy. Gee, how hard is it to move a BC and reg?


I also have really good air consumption rates. It is rare to come up with less than 1400 lbs of air in my tanks. I try to arrange small tanks from the dive operation, if I can. Otherwise, I just bring back the air. I use it to practise many air rings during the safety stops. I feel secure that I would have plenty to spare, just in case.....

[acelockco]

Gee, how hard is it to move a BC and reg?

It is very easy to move a BC and reg, but to change over from a single cylinder to a double cylinder is a major change that usually requires tools and adaptors. Plus you will need an additional cylinder or a replacement valve and someone to inspect and fill your cylinder.

[bottlefish]

QUOTE=bottlefish;8924]Hmm, re-educate, or find a new dive team :-)

Getting out of the water for doubles? Ah, well that sort of divings not for women really, they're too weak and fragile... OK, that was in bad taste (sorry!).

Whew! I don't trust myself to reply to this!

Just thought I should clarify, my comment was totally tongue in cheek, not at all serious and totally opposite to my true opinion; just a gentle reference to another post by LittleLemur, "Why are scuba chix ridiculed/not taken seriously by guys" that was running at the same time

http://www.scubamagazine.net/showthr...?t=1289&page=2

Apologies for any elevated blood pressures caused

Re the original question, how much money would be returned if the dive centre/boat in question refunded you for that second air fill and tank hire, or put another way, how much would they charge you if you rocked up with your own tanks? Surely you're only talking about a couple dollars for the fill, the majority of the money paid goes towards the space on the boat, and the cost of running the boat?