H2Odyssey's EAS 2

[peterjmaerz]

Hello Wet Ones,

I've done the requisite search on the board and mostly found variations of the old spare air--to use or not to use-- debate.

Lately, I've been diving solo either literally or for all intents and purposes . I'm not going to cart around a full size pony bottle but I am considering the 6 cu ft variety noted above. I'm curious about any diving photogs who use them.

If you're one of them, how does it affect your buouyancy? You're freedom of movement? Your ability to take photos? Your trim and ability to position yourself in tight spaces?

What about entries and exits?


Thanks for your time,


Best Regards,

 

[rpodos]

There was a review of the various smaller spares in Scuba Diver earlier this year... sorry, don't remember which issue.

 

[teknitroxdiver]

Well, lets take a look at it:

A 6cf Luxfer is 3.2" around, 11" long, and swings from -1.3 to -.9 from full to empty. The only real way to mount a tank this small is either on the primary tank (which increases the chance of entanglement, and you can't see if it's leaking, which is important because it doesn't take much of a leak to bleed out 6cf) or mounted as you would an argon bottle, if you have a bp/w. With a jacket bc it'll have to be tank mounted.

Now for the practicality of the 6cf:

You say you're diving solo, and have 200+ dives, so I'll assume your SAC rate is pretty good, say around .5....in an emergency that will go up...let's use .65 as an example. To make the math easy, let's assume a dive to 66 feet (3 ATA). At that depth, you're consuming air at a rate of 1.95cf per minute...the tank will last you 3 minutes. At an ascent rate of 30fpm, it will take you 2 minutes and some change to get to the surface. Add a safety stop to that. Now you've got a total ascent time of 5 minutes. Even assuming that your air consumption rate will go down as you ascend, you will likely drain the tank before finishing the safety stop...especially if you have to deal with a problem on the bottom first, for example if you're tangled in something.

Now a somewhat deeper dive, 99 feet (again to keep the math simple). That's 4 ATA so now you're consuming air at 2.6cfm...the tank will last you 2 minutes and 18 seconds at depth. Ascending from that depth will take about 3 minutes and 20 seconds. Since you've most likely switched to the pony because you used up all in your main tank, you've been down at 100 feet for a while, so blowing off the safety stop might not be real good. In this case you won't make it to the surface, let alone make a 3-5 minute stop on the 6 cf bottle. Throw in a 1 minute deep stop at, say, 50 feet, and you're for sure not going to make it.


What reasons did you have for not wanting to use a larger bottle? A larger one would actually be easier to mount, and would give you a lot more options, for example, if you were a ways away from the anchor line, you could choose to swim back to the boat before ascending, instead of surfacing away from the dive flag and away from the boat. Also, just knowing that you had plenty of air to work with can have a calming effect, and encourage you to make that safety stop and to ascend slowly.

 

[navillus]

TekNitrox makes some excellent points. I do not solo dive, and am relatively new to diving in general. I am buying a saftey bottle for myself for when I do some deeper rec dives with my buddy. (Actually this will be my wife's bottle, but since she is newly pregnant, I will get to use it as a safety bottle with her regs on it for at least the next 9 months). I am going with the PST E7-80. It is 1/3 smaller than a typical Al-80, lighter, and is negatively bouyant.

PST is running a special on their e7-80's. I called them yesterday and they said that their MSRP is $179.99, which is not to terribly much more than an AL 80. Do you think something like that could help?

 

[StSomewhere]

Are you sure you want a steel stage/pony bottle?

 

[navillus]

I should qualify what I meant with the e7-80. Could you take it with you and leave it somewhere around you that you could swim to in an emergency (if you are near the bottom) or hang it off of a boat at about 20 ft (or deeper if you are diving deeper)? This way your bouyancy would not be effected, and you still have that safety bottle when you need it (as long as you stick around and remember where it is). Just thoughts of a newbie. . .

 

[teknitroxdiver]

No. When you need it, you need it. If you're out of air (which is about the only time you would need a pony) you need it NOW, not after you swim to the anchor, or make a CESA to 20 feet, again returning to the anchor line.

The best thing to do is get a Luxfer 30 or 40 cf, put a loop of line around the neck and a hose clamp 3/4 down the bottle, run a line under both with a bolt snap at each end. Clip the top snap to your left shoulder D-ring and the bottom snap to your left hip D-ring. The butt of it floats up under your arm, and doesn't add any drag. This way you can have it handy on you, see if anything is leaking, and keep it where it doesn't add any drag.

 

[peterjmaerz]

Hi Teknitroxdiver,


And thanks for your very detailed and reasonable response to my querry about the EAS from H2Odyssey. I'm not up on my air consumption rate, though I'n sure your'e very knowdledgeable about these things. What I don't understand is the disparity in calculations between tech divers (as I suggested in my original post, I've read many ardent discussions on the value/uselessness of spare air type products) and folks who review these things.

While I'm not so naive as to think that there's no commercial incentive for magazines to praise the products of manufacturers who advertise with them, it seems to me it would be legally negligent to make a claim, as was the case in a recent SubaDiving article, that the 6 ft H2Odyssey EAS tank was (paraphrasing) the only one of the spare air products that allowed for an easy descent from 100 ft with room for a safety stop and a few extra breaths on top of that. How can their tests be so far off the mark?

The EAS system, by the way, is carried in a sling of sorts that clips onto D-rings on the front of the BC. (I use a TransPac w/out BP). I'm no techie--my diving involves mostly leisurely glides in search of photo subjects. My gear (including an Atomics M1)is kept meticulously, inspected regularly and I check my gauges every couple of minutes while diving. I do enjoy the occasional wreck dive, but never penetrate other than the mildest, easiest entries.

I understand that risk is always present in diving. I'm not a macho, devil-may-care type. But the likelihood of my "running out of air" is slim. What I'm looking at is the highly unlikely event of a massive equipment failure. IN that event, I'd like to be able to get to the surface without dying. I'd hate to get bent, of course, but a minor hit would be worth the avoidance of carrying around a 30cf cylinder to my mind.

I'm most interested in finding out how UWP's are affected by carrying around the H2Oodyssey.



OK, it's open season! Have at me.

And thanks again for the input.

regards,

 

[Miami_Diver]

Hello Wet Ones,

I've done the requisite search on the board and mostly found variations of the old spare air--to use or not to use-- debate.

Lately, I've been diving solo either literally or for all intents and purposes . I'm not going to cart around a full size pony bottle but I am considering the 6 cu ft variety noted above. I'm curious about any diving photogs who use them.

If you're one of them, how does it affect your buouyancy? You're freedom of movement? Your ability to take photos? Your trim and ability to position yourself in tight spaces?

What about entries and exits?


Thanks for your time,


Best Regards,

I have a oddyssey extra air and love it. its relaxing to know that if anything goes wrong withing recreational limits is there for you and big enough 6cu, to make a controll acent without looking for your buddy.
I got it off LP you can buy a carry bag that comes with 2 clamps that you can attached to a ring on your BC. its barely negative when full so it hangs out of the way and doesnt bother me.

go to scubadiving.com and on the search put "extra air" and look for the article "bailout bottles" they did an independent test .and you CAN make a CONTROLL accent from 130 ft. with breaths to spair.

 

[teknitroxdiver]

...without looking for your buddy.

IMO, it would be much better to have enough gas to return to your buddy, tell him what's going on, then surface together, instead of leaving your buddy (who likely has no 'pony bottle' of his own) without assistance if he were to need it shortly after you departed for the surface.