What's wrong with the HUB?

Before you move on to the rest of the page, I'd just like to clarify something.
Since writing this article, I've had numerous people ask why I seem to have such hatred for this piece of equipment.
I don't.
I care no more about the HUB than any other dive shop gimmick. It makes absolutely no difference to me how loved or loathed the HUB is.
What I do hate is the way people would ask, in all innocence, "Should I buy a HUB?" on a forum, and it would start a week-long flame war.
This page was originally a fairly short summary of all the things that people posted as being wrong with the HUB, written in hopes it would stop the tedious arguments. It worked. It still works, which is why it still exists.
It has grown over the years as many people have pointed out more and more flaws - including HUB owners and (more usually) ex-HUB owners.
If you own a HUB and like it, good luck to you. I wish you joy of it. But don't bother to email me to tell me about it, because I really couldn't care less.
Thank you.

So, the Mares HUB, Human Underwater Breathing.

Advantages: None
Okay, you may not agree with that. But it's true, as far as I can tell. To have some points to discuss, though, I'll include the advertised advantages:
Neat hose routing
Easy to set up and use
Buy all your kit in one integrated unit

That's about it.

Now let's apply rational thought to the HUB, and compare it to what's written in the brochures.

Firstly, the integrated approach means you have the problem that the HUB is an "all or nothing" piece of kit. Every part of it has to be working, or you can't use any of it.
For instance:
Normal diver "My BC has a puncture"
Buddy: "No problem, I have a spare one"
Normal diver: "Great, let's go"

HUB diver: "My BC has a puncture"
Buddy: "No problem, I have a spare one"
HUB diver: "Got a spare regulator as well..?"

HUB AvantGarde diver: "My BC has a puncture"
Buddy: "No problem, I have a spare one"
HUB AvantGarde diver: "Got a spare regulator and weight harness as well..?"

With the possible exception of a demand valve fault, where you may be able to swap in a spare, a single failure will knock out your whole aqualung.

It doesn't even take a failure: A normal diver can send one part of his kit in for service, and use the rest of his kit along with borrowed or his own spare gear. A HUB user sends his entire kit in for servicing, and needs an entire spare HUB to carry on diving. If forced to hire replacements, the HUB diver will almost certainly have to hire 'standard' gear, which means that he'll be diving with a totally unfamiliar piece setup, instead of just a slightly different one.

Next, there's the octopus.
With the number of divers and every training agency stressing that the octopus must be instantly available, the idea of stuffing your octopus away in a pocket simply defies belief.

If your buddy is out of air, he needs a reg instantly. Asphyxiating divers will not wait for you to fumble them a demand valve. If you can't give him your octopus immediately, you'll be loosing the reg from your mouth, it's as simple as that. And then YOU are the OOA diver.
How fast can you pull an octopus out of its pocket, untangle the hose, get it right way up, and get it to the mouth requiring it?

Another issue is the way you access the octopus: It's in its pocket, and you release it by pulling on a toggle. That was bad enough on the HUB, but on the avantgarde, it's plain dangerous. Why? Because of the weights.
The HUB has no integrated weights. But a large number of divers have weight harnesses instead of belts these days. The avantgarde, of course, IS integrated.
Now, I hate weight belts, and have no problem with integrated BCDs per se: My own rig has integrated weights. But if you or your buddy are trained to go for a handle on your BC when in an OOA situation, which is what the HUB demands, then there's a very real risk that in the stress of the moment, you'll latch on to the integrated or harnessed weights instead of the octopus pocket.
Picture the situation: Your buddy is OOA. He's panicking, and not thinking rationally. He swims to you, he grabs the first toggle he sees on your right hand side. He yanks on it, and suddenly is holding several pounds of lead. You are immediately uncontrollably buoyant, and go up fast. He's now negative, and sinks. He is still OOA, and has made the situation worse by making it impossible to get air from you. He has no choice but to make an emergency ascent.
You'll BOTH be lucky if you make it to the surface both alive and unbent.

Failure points. Another big concern. A normal diver's setup of two second stages, an SPG and one or two direct feeds has a number of failure points.
Every piece of equipment is a failure point. Even more risky is the number of connections between hose and instrument. A number of twinset users deride the practice of carrying two SPGs, for the simple reason it adds failure points without adding value.
Every piece of equipment you carry should be carefully considered: Do the potential advantages offset the potential risks? How do you minimise the impact of a failure? And so on.
What is the HUB like from a failure points perspective? It's appalling.
For starters, both second stages are fed from one hose, with a splitter at the end. If that hose or the splitter goes, you have no air from eitherof your second stages - do you really want a system where a single failure can kill your entire breathing supply?
And then there's the way a lot of the hoses are inside the BC. You can't see them, you can't inspect them, but the HUB does NOT remove hoses. It just hides them. The HUB markets itself as being a simple system with minimal hoses. This is not true, it's just that you can't SEE the multitude of hoses. What's more, it drastically over-complicates things with hose splitters, manifolds and so on, all of which are adding totally unnecessary failure points. And you can't even see if they go wrong! They're hidden away from you.

As a simple example, consider the number of failure points between a first stage and a demand valve on a normal and a HUB setup:

A HUB has more connections than a twinset diver with a decompression stage, and absolutely none of the redundancy.
Other failure points: The Airlock camband. A wonderful solution to a problem that doesn't exist (rather like the HUB itself really). You put the band on, hit the inflator (which in itself is another piece of equipment on another hose which means even MORE regulator failure points) and it pulls the band tight and holds it.
Compared to the normal method of pulling a camband tight and then closing the buckle, I fail to see any advantage.
Some people say "I've seen cylinders fall off people with cambands, they're dangerous". That's not a failure of the camband, it's a failure of the user. Learn how to tighten a camband, don't add lord knows how many failure points to your kit to compensate for your own bad practices.
The inflate/deflate controls. Even MORE failure points added, you're using a complex pneumatic system to open the dump valves. Exactly what's so hard about using a manual dump? Raising the corrugated tube can be a bit of a pain, esp. in a drysuit with a cuff dump. So use the right shoulder dump with a pull cord. It's a lot less complex than the pneumatic dumps on a HUB.

Which leads on to another problem the HUB brings up: It's dangerously non-standard. Instead of a corrugated hose, it has a little grippy-thing on the left pocket. Nicely situated for it's wearer. A total pain for a rescuer to reach in the event of you having a problem. A corrugated hose can be held firmly by the rescuer throughout a descent, the HUB control cannot. And that's assuming that your rescuer knows how the HUB works - your rescuer isn't always your buddy. If a diver finds a casualty with no apparent inflate control, he's going to waste a lot of time trying to get you back to the surface. Time you might not have to spare.

Streamlining: The HUB is a stab jacket BC, which is a long way from being the most streamlined type. You want a streamlined BC, get a wing. The only thing a HUB does to contribute to streamlining is to hide the hoses.
Just how much drag do a couple of hoses generate??
And let's not forget, on a normal setup, none of your hoses should be sticking out or free to hang around anyway. They should all be clipped in place, close to your body, no exceptions. You don't need to buy a HUB to tidy your hoses, you need a couple of hose clips.
Additional cost for clips? About a fiver.
Additional cost of a HUB? Exorbitant.
Your octopus should be fixed somewhere you can reach and deploy it instantly, your console/SPG should be clipped where you can find it and look at it quickly and easily. Hiding it away in a pocket doesn't count as easily accessible in my book.

Better buoyancy distribution: The wonderful dragonfly design. The back inflates first, and then the front/side sections. Gives you all the buoyancy advantages of a wing, without the loss of stability on the surface. Better than a wing, allegedly.
Great. Except that any BC will always hold air in the back rather than the front when you're in your usual horizontal diving position, because air rises in water, remember? And a wing doesn't give you bad surface stability, and it doesn't push you face-down into the water. Not unless you've got serious problems with your trim.
Not to mention the fact that a wing and backplate is adjustable to an unlimited degree, can be used for any number of cylinders, is a much less cluttered design, is more versatile, and is way, way cheaper than a HUB. And has less failure points too.
And let's not forget quantity as well as quality - the HUB comes in four sizes. The smallest has a maximum lift on 24lbs ~ 11kg. The largest has 37lbs ~ 17kg. This is probably ok for warm-water diving, but it's rather marginal for a drysuited diver, especially if you throw in a pony, which is a common enough bit of kit these days.

Easy to set up. Hmm. A normal kit setup, you put your camband round the cylinder, attach the first stage, and off you go. A HUB, you attach the BC to the cylinder, attach the first stage, and off you go. The avantgarde, you attach to the cylinder, attach your first stage, activate your ludicrous inflatable camband, and off you go. Gee, the difference is amazing.
Incidentally, take a look at Mares' photo of the avantgarde, and tell me that it looks simple and streamlined.

Weight. All the gadgets and extra hoses on the HUB make for a fairly weighty package. Not what you want if you want to take it on diving holidays, really.

And then there's the "buying all your kit in one go". If you buy a HUB, you'll pay MORE than you would for a comparable BC and the same set of regs. If you buy the avantgarde, you'll also pay more than the normal total cost of the individual units. And if I were to go do a dive shop and buy a BCD AND a full set of regs AND weights, not only would I expect to pay less than I would for the HUB equivalent, I'd expect a further discount for buying in bulk!
However, something worth noting at this point is that I have never, ever seen a HUB in a dive shop that wasn't on sale. It appears that nobody will buy it unless it's on special offer. A thought that really fills you with confidence.

If you want a streamlined set of kit with no dangling hoses that's easy to set up and use, look up the Hogarthian setup. If you just want to avoid dangling hoses, buy a couple of clips. If you want nothing but simplicity, buy a Mini-B. If you want to look like an uninformed novice with more money than sense, buy a HUB.

In closing, for those who've never seen it, this is the nightmare of hose-spitters and manifolds that the HUB has inside it:

Note the way the first stage at the top connects to the splitter at the bottom via two bent (and therefore strained) hoses - one of which is a high-pressure hose, I believe.

Note the way a single hose goes to the pocket, where it splits and feeds BOTH second stages - allowing a single failure to cut your entire supply of breathing air.

Note the way the DV will either be pulling downwards the whole time, or need an elbow joint added, adding yet more failure points.

There have been a few attempts at rebuttals to this article since I wrote it. One such is HERE

And finally, a few quotes from other people about their experiences with HUBs:

although I have never dived it, I had a look at it in the shop and was not impressed. It just seems too complicated. I would not want to wear the jacket in an emergency situation. How did anybody come up with the idea to but the octopus in a pocket! In an emergency I definitely do not want to have to fiddle to open a pocket just to get to my potentially life saving octopus.

I went over one in a shop when they first came out and its complications have even more complications inside them. Even the shop keeper admitted that he'd tried it in the water and he wasn't anxious to do so again.

I didn't actually feel comfortable wearing the HUB at the Dive show last year, even compared to a BCD it felt for want of a better word clustrophobic. I can't quite put my finger on what was wrong it just didn't feel 'right' and as I've been told on various occasions your gut feeling is normally correct.

Someone in our branch bought one against all advice and sold it soon after for a lot less than he paid. I tried it in the pool and I have to say it was very comfortable to wear. BUT...
It is very expensive.
It is very heavy.
Most of the potential leak points are hidden away inside the jacket.
The octopus is diffficult to access as it's coiled away in a pocket.
The hose route for the 2nd stage looks like a good idea but it's very uncomfortable. It needs a swivel joint to stop it twisting in the mouth and my arm kept hiting the loop of the hose.

I have been using a HUB (mares version rather than the Dacor) for about three years
Bad points:
The whole package is a bit heavy (I end up using very little addition weight).
The pockets don't hold much (a big metal connector in one and my backup console in the other), don't put anything small in them (a sharks tooth) as they both have holes for routing various hoses.
The oral inflator is pathetic (although I've never had to use it).
All of your eggs are in one basket, so make sure you get it serviced regularly.

I can post as a (now ex) HUB owner.
The HUB is a very convienient system to use, as all your kit is readily connected. Just put on the jacket and go. As mentioned in another post, it is, however quite (very if you ask my wife) heavy - there are several manifolds behind the backplate / in the pockets. This is a pain for traveling and makes it more difficult to get on with the integrated weights in place. Incidentally the integrated weights have fallen out of our BC's twice. The system is a push lock with no velcro.
You mentioned that you wanted to stay with a jacket style BCD - the HUB is a semi wing style BC, which uses Mares power inflator / deflator airtrim system. The inflator / deflator falls easily to hand and is comfortably to use, however the power deflator lacks finess in my opinion - it has a switch like feel rather than the progressive nature of a conventional deflator. This takes time to get used to and can mess up your bouyancy control for some time. Also, the deflator valves are located on the shoulder portion and hip of the BC, rather than the top of the wing - this inevitably leads to an amount of air becoming trapped in the top of the wing during head up ascents / safety stops which can be frustrating as you have to assume a head down position to vent all your air.
Another drawback of having the convienience of regs and gauges permanently attached, is that there is very little pocket space for SMB / torch etc. which is frustrating, OK so no drag from having octopus and gauges trailing in the slipstream, but then you have to clip your SMB / camera whatever to D rings.
The power assisted tank band is ace, the envy of other divers (but heavy). It's safe, too.
The overall quality of the system is feels good.
The backpack you get is useful for draining and storage, but the straps are like cheese wires if you need to carry it on your back. Not the best use of a good idea.
As I say, I'm an ex-HUB owner. I couldn't put up with it - tried for 40 odd dives before selling it on. I now have seac sub pro3000 / MK25/X650. The seac sub BC is sooooooo much more comfortable, has massive pockets and loads more lift.

I bought one when I returned to diving a couple of years ago after a long break. It seemed like a good idea at the time.
The sensation of wearing one is comparable to wearing a thick overcoat whilst driving: there's just too much of damn thing.
It completely covers the front of your body with huge pockets that you can't get to. It's like wearing one of those joke Sumo suits.
The octopus, buried away in a pocket with velcro that would put good welding to shame, may as well be back on the boat for all the confidence it inspires. They weigh a ton. And, get this, you don't even get an SPG with it, which seems a bit tight for the price as I don't consider a pressure gauge to be an optional extra when diving.
Fortunately I realised the error of my ways before I'd used it for proper diving and was lucky enough to get almost all that I paid for it when I sold it on eBay.
If you really want one of these things after hearing what is almost 100% negative reports, I's suggest looking on eBay, 'cos they appear quite regularly and are almost all virtually new and unused.

I bought a Mares HUB earlier this year from new because it looked so nice and the general idea is a good one, however I did one dive in it at Capernwray in a drysuit and sold it on eBay!! Some people said I should have given in more of a chance, but I just wanted to get rid (total waste of money, I lost a fortune!!). The main compalints were:
*) Considering it is supposed to be easy to sent up, it was actually a pain in the ar*se getting the airlock to work
*) The pockets continually fell open on the dive as the velcro couldn't hold them, and so the octo would free flow
*)You would definately need a swivel for the second stage, or the mouth piece feels like it is being dragged out of you mouth the whole time as it's configured at such an angle
*) It weighs a tonne, even the bag it comes in does not make carrying it around any easier
*) And to top it off, I spoke to my LDS and they quoted me nearly 100 for servicing as they have to be sent back to Mares, 3 week turn around!!!!

Thanks to the folk on UKRS and Divernet for these final insights...

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