Aqua Lung Axiom i3 BCD -- Thoughts on i3 Inflator Mechanism

[diversteve]

Far easier than trying to get fresh water into a BC using a conventional inflator.

Not really...this one takes a standard garden hose.



Zeagle Bx Power Inflator 112-1001BX

The fundamental problem with the I3 is it violates a cardinal rule of diving - K.I.S.S. by needlessly complicating a design that's been proven for decades for the convenience of pushing a lever to ascend/descend.

A standard inflator has a rubber hose, a schrader valve (there's 4 on your car tires) and a couple other simple moving parts (depends on whose) for reliability. An I3 does the exact same job with a lever, a complicated arrangements of valves. at least 4 internal o-rings, a proprietary linkage to each dump valve, proprietary dump valves and they're even more proprietary than the the standard Aqualung flat valves since they both have to be "wired" for the linkage and have a check valve so water can't get in.

Simple basic grade school physics taught us that an air bubble seeks the highest point. So that's the only point worth venting. Because AL decided to open all the valves, they have to provide 3 additional check valves so that the two that are doing no good at the time don't actually leak water into the BC during venting. Huh?

Let's address rescue also. One of the posters in this thread mentions demonstrating your I3 to your buddy. That assumes that buddy is the person who might have to rescue you. What if it's someone else on the boat? Or in the case of places like Cozumel, someone else from another boat also drifting by? If we make the basic assumption that you're incapacitated for some reason, it's logical that the person attempting to save you isn't going to reliably notice that you're diving an Aqualung I3 and that they need to locate the handle at your side to stop your descent. And when they go to grab your power inflator hose, it's not where they expect it to be either but hidden under a flap on your shoulder.

Also Aqualung has locked you into their system by requiring that all service be done by an Aqualung trained technician using Aqualung Priced Proprietary parts. What do they get for those custom flat valves anyway? Or the handle mechanism when the guy next to you drops his tank on it?

One of the best examples I know of why KISS works. We're on a liveaboard - one day from port (3 hrs.) Guy next to me powers up his gear and we hear a hissing from the inflator. He picks it up and the button pops off in his hand. The spring however flies onto the deck and we both watch it roll through an opening and fall overboard. The DM sees this, laughs and comes back in 2mins. with one he cut off another rental BC. 2 cable ties later and the guy gets to dive his BC for the rest of the trip. Didn't even miss that dive. In all fairness Aggressor is an Aqualung partner so there's a possibility they have both I3 parts and the trained technician on board to fix an I3 on the spot but that would require at least sitting out that dive. Not so on the boat I was on though.

I don't haul my gear all over to not dive it when I can't locate a factory authorized service center for needed parts/repairs in the field. Although AL actually IMO has one of the better worldwide coverage areas - they're still not everywhere. I don't recall seeing an AL dealer on Roatan for example - most would agree that's a popular dive destination.

 

[g1138]

You remove your power inflator from the 2" corrugated hose to fill your BCD with fresh water? Or your power inflator has a 2" orifice?

Fair enough.

woop woop woop......

3/4in orfice to a 2in corrugated hose?

 

[diversteve]

I thought all standard inflator hoses were 1" I.D.?

 

[Ima wet]

If it makes you feel better you can install a traditional inflator. It would be a bit redundant but it's an option.

 

[60plus]

I felt the i3 system was more to go wrong so I bought the non i3 axiom bcd which I really like. One improvement Aqualung could make is to color the ditchable weight [pockets a bright fluorescent color.

 

[Wibble]

An alternative viewpoint...

The i3 is non standard for most divers. If you need rescuing or another diver needs to dump some of the gas from it, there’s no elephant's trunk to grab and dump from. Similarly inflation is not where it’s expected. Manual inflate is hidden.

Imagine an out of gas scenario where you’re sharing gas from an octopus of some random rescuer who needs to control the ascent. Not good if they can’t easily access the dump or cannot find it.

On the surface you need to inflate it manually, how easy is it with the skinny, hidden, inflate pipe? Ditto for a rescuer. How often do you practice manual inflation?

i3's are purchased by novices who may well find themselves in need of assistance.

 

[yle]

An alternative viewpoint...

The i3 is non standard for most divers. If you need rescuing or another diver needs to dump some of the gas from it, there’s no elephant's trunk to grab and dump from. Similarly inflation is not where it’s expected. Manual inflate is hidden.

Imagine an out of gas scenario where you’re sharing gas from an octopus of some random rescuer who needs to control the ascent. Not good if they can’t easily access the dump or cannot find it.

On the surface you need to inflate it manually, how easy is it with the skinny, hidden, inflate pipe? Ditto for a rescuer. How often do you practice manual inflation?

i3's are purchased by novices who may well find themselves in need of assistance.

I can add my two cents to the discussion.

As a new diver, I bought a Pro QD with i3 (the early version... they improved on it later) in 2007. It worked fine, I never had a problem with it.

Over the years I would jump through the courses necessary to become an instructor. And when I started teaching, I realized my trusty ol Pro QD with i3 presented a problem. Fortunately our rental gear was the same Aqualung BCD, just with a traditional inflator. And fortunately I could add a traditional inflator to my Pro QD so that my BCD functioned exactly the same way as my students' BCDs. I could also still use the i3 lever to open all my dump valves at once, if I wanted to.

In retrospect, I'm not a big fan of the i3. But that's mostly because I've had the opportunity to teach a lot of new divers and see, through that lens, the potential problems that could occur with the i3 system... problems you mention above. The oral inflate workaround for the i3 is a bit awkward, if only because it's unfamiliar to just about everyone (and the last thing anyone needs in a situation where the oral inflate is necessary is "unfamiliar".)

The system, as has been pointed out in earlier posts, is prone to failure. My mother bought an i3 BCD when she started diving; years later the tube/wire system that activates the valves had a problem. The shop she took it to told her it couldn't be repaired and offered to sell her a new BCD. She was smart enough to ignore that suggestion, brought it home. I added a traditional inflator and manual pulls to her valves and it works just fine (the i3 lever is there... just doesn't do anything.)

While the system is nice and convenient when it functions properly (which is most of the time), I think the disadvantages (added cost, complexity, unfamiliarity for divers offering assistance) outweigh the advantages.

 

[Wibble]

Personal opinion of the i3...

It's exploitative. New divers that don't know a BCD from an SPG get 'recommended' those by a dive shop on spurious benefits. It's a complex system that has many drawbacks and few -- if any -- benefits. Is it sold as there's a big margin on that kit?

Divers with a little more experience, especially those who've been through Rescue Diver, will realise that the alleged problem the i3 "solves" does not exist.

"You can deflate facing in any direction; head pointing down, upwards or even sideways. With a traditional deflation system you have to face upright which is counter intuitive if you wish to descend. It also means you can easily deflate if you are swimming through a tight swim-through."

That's complete nonsense. All BCDs have a lower dump, some have dumps on both sides. When you're vertical, you use the elephant's trunk for deflation and inflation; when horizontal (down or sideways) you use the lower dump and the elephant's trunk to inflate. When a novice diver's stressed or in difficulty, they will naturally go vertical. Similarly novice divers most often ascend in a vertical trim (not least to see above and around them).

As said in posts above, dive kit should be simple and obvious. There's a reason why all jacket BCDs (except the i3) have an elephant's trunk on the left shoulder and at least one pull-dump on the bottom. Contrary to the marketing fluff on the i3, this isn't because the industry is slow to innovate or copy each other, it's because standards improve safety.

Other BCDs are cheaper too (and standard, more reliable, cheaper to service, easy to repair, use easily available parts...).

 

[ljpm]

I purchase an i3 when I started diving. Initially I loved it, perhaps to much. It was to easy to add and remove air. I also experienced a failure of the system while in Roatan. I simply switched to the shoulder dump for the trip and sent it out for repair when I got home. I honestly don't remember the cost although I think it was covered under warranty but I had to pay shipping (again not 100% sure of that). My wife and daughter, and son when she out grew it, both have i3s with no issues for 8 years.

One issue that I didn't see mentioned (could have missed it) is that the i3 switch is in a bad location if you want to sling a pony/stage. This wont' be a problem for most but if you are planning on more technical diving or solo diving it is something to consider. I was able to use the i3 but the pony could get in the way. Also, I don't know how the switch would hold up long term with a pony banging against it. I only used it once with a pony. I switch to a backplate wing a couple of years ago so no longer use the i3.

Edit: need to clarify. The failure was only on the dump system. I could add air but could not dump with the i3. I therefore used the shoulder dump.

 

[Wibble]

[QUOTE="ljpm, post: 9276399, member: 468999" I also experienced a failure of the system while in Roatan. I simply switched to the shoulder dump for the trip and sent it out for repair when I got home. .[/QUOTE]

Did yours have the 'elephant's trunk' style shoulder inflator / deflator?

It was mentioned on one of the i3 sites that this was an option for instructors to be able to demonstrate standard dumping techniques.