The Mares & Dacor HUB

[Northeastwrecks]

Zagnut once bubbled...
Have any of y'all DIR Nazis (just a joke...lighten up! ) have ever experienced discomfort with your spine making contact with the plate?

Actually, just the opposite.

Prior to finding the ONE TRUE WAY (this is a joke), I had a soft back BC (Zeagle Tech). I found that my back was much more tired and sore after diving with it than it is when I dive with my BP.

I don't particularly notice any real contact with my spine.

 

[metridium]

Zagnut wrote...
Have any of y'all DIR Nazis (just a joke...lighten up! ) have ever experienced discomfort with your spine making contact with the plate?

Though I'm not DIR (Nazi or otherwise), I've been diving BPs for around six years. Can I still answer?



Even with the bolts from doubles or my old STA, which are secured by wingnuts inside the channel, I've never noticed any spinal discomfort related to the backplate.

 

[wetlettuce]

Hi

It wasn't the failure point issue that really caused me to change from the HUB to BP and wing, it was the fact that I lost confidence in the HUB and found what I believe is a better configuration.

I dive virtually every weekend usually in a drysuit in the North Sea off a RIB. For holiday diving we are going to red sea on a liveaboard during June and again in September. I didn't want to lose out if my kit went wrong.

The Axis octopus leaked twice during my HUB use. Once while preparing for a dive, but I had a spare reg and put that on. Sent it back for warranty and they fixed it fine. The velcro started to come undone where the octopus goes in the pocket. It was again sent back and got fixed. The second time the octopus leaked was during an instructor course in a pool. After the Hub was fully dried out the octopus stopped leaking.

When I lost a days diving in Oban it was simply an O ring in the A Clamp. I didn't know at the time and took it to Puffin divers who said it was a hose that had failed and they didn't have a spare and a standard hose wouldn't fit.It just didn't inspire confidence seeing as I dive virtually every weekend and have a liveaboard holiday lined up.

And all this happened within 8 months of buying it.

I don't believe the HUB is more expensive. It cost more to kit out the girlfriend with Scubapro MK25, S600, R380 and a Seaquest Diva jacket which she loves.

The Orbiter reg is excellent and I never had a problem with it, indeed it will be in my dive bag as a spare during my holiday just in case my aqualung legends fail.

During a search for configuring a twinset I found this board, through a review from a guy who had made his own harness and following that I spent a lot of time reading stuff about DIR and kit configuration. I liked the idea about standard hoses, safer DIN regs and the long hose setup.

Sometimes using the HUB became inconvenient. One thing I noted about the HUB was it was a PITA doing a buddy check because the octopus was hard to restow after showing it to the buddy and sometimes I didn't even check it. With the long hose setup I can check both regs and it just FEELS so much more efficient and I have found that buddies understand the system better than a clipped off octopus.

I did quite like the power inflator but on my hub it doesn't dump when you are perfectly horizontal, I can't speak for others. When you look at the placement of the dumps, on on the bottom pointing up, on on the shoulder pointing down, if you were swimming horizontalthen you would have to lift your bum up to move air to the dump. Its not a problem, but it means that to me it was no different to any other BC. With the 'elephants trunk' bungied to the Dring I always know where it is anyway and so this has the same effect. The halcyon BC also doesn't dump when completely horizontal and so diving is the same.

Having no pockets in the front of my drysuit/wetsuit means it is a lot less bulky and I can actually lean over to get my fins on easier. I like the fact that I can look down and see behind me. With the HUB you couldn't put stuff in the pockets anyway so I like BP/Wing much more. I also felt bulky particularly in a drysuit with the chest strap and a 15ltr and 3ltr pony attached (the pony meaning added hoses which I couldn't integrate.

I considered stripping the HUB and making it a standard Dragonfly but would need a longer inflator hose and a new first stage. Not a quick fix!

I like to think of myself as a logical person and the DIR kit configuration (even after the initial defensive 'what do they know about UK diving' reaction) makes logical sense to me. The HUB is a jacket BC. The hose layout is a minor issue compared to the ease of use with a BP and wing. I have tried them both and this is my conclusion. Each time I dive with BP and wing I like it more and more.

Hope that helps

WetLettuce

 

[Rick Murchison]

Having come from the backpack only up through the milk jug, horse collar/Mae West, vest, jacket, BP/Wing, I find myself reserving my BP for doubles. With singles I wear either a Transpac or a jacket, depending on where and why I'm diving. My personal opinion borne of my personal experience is that for the occasional diver who's diving AL 80's in (relatively) warm water, one of the light-weight jackets is the optimum rig.
Rick

 

[Ian Wigg]

Diver0001 once bubbled...


Ian,

... (1) checking your hoses is more difficult and I believe that most HUB users won't even bother ...

R..

Perhaps you could be more specific as to what you are implying here.

By the way - did you know that the statistical chance of a hose failing increases exponentialy for a given linear increase in its length so if you compare the total hose length on a HUB and a long hose bp/wing setup you can compare the statistical chance of such a failure occuring - be interesting to see which is higher.
I'll measure the hose length on the HUB.

Ian

 

[MikeS]

Ian Wigg once bubbled...

By the way - did you know that the statistical chance of a hose failing increases exponentialy for a given linear increase in its length ...
Ian

Ian,

Do you have data to support this? I would guess that if the cables are regularly inspected for deterioration, the vast majority of failures will occur at the connectors, as that is where the most stress occurs. That would mean that the length of the hose had minimal contribution to the MTTF.

Mike

 

[Ian Wigg]

MikeS once bubbled...


Ian,

Do you have data to support this? I would guess that if the cables are regularly inspected for deterioration, the vast majority of failures will occur at the connectors, as that is where the most stress occurs. That would mean that the length of the hose had minimal contribution to the MTTF.

Mike

I'll see if I can dig out the data but if you think about it, on a purely logical basis it makes mathematical sense. This is why, in all systems (not just scuba), hose lengths are kept within carefully calculated parameters.

In regards the connectors a number of factors will apply such as how often the connector is disturbed - hence o-ring failure at the tank valve probably being the highest risk.

The argument could be put forward that, due to the fact that the hoses on the HUB are routed within the jacket, they are going to be subject to less risk of abrasion and/or cuts and, therefore present a lower risk of failure than a ' standard' setup.

At the end of the day it's going to boil down to what sort of diving you plan to do, personal preference, and cost.

 

[Diver0001]

Ian Wigg once bubbled...


Perhaps you could be more specific as to what you are implying here.

By the way - did you know that the statistical chance of a hose failing increases exponentialy for a given linear increase in its length so if you compare the total hose length on a HUB and a long hose bp/wing setup you can compare the statistical chance of such a failure occuring - be interesting to see which is higher.
I'll measure the hose length on the HUB.

Ian

Hi Ian,

I'm saying that I don't think it's easy to check the regulator hoses, especially the hidden bits behind your back. The joint behind your back is critical and should be checked before every dive (just like the one in your pocket) but I'm not convinced that most HUB owners are even aware of this. Many may also not feel the need to check them, just as many divers with traditional kit don't check their hoses regularly. The difference with teh HUB is that failing hoses stand a better chance of going unnoticed because they're out of sight. It's not a cheap jab. I'm more straightforward than that.

I'm interested in the statistics you mentioned. I've always assumed that the number of connection points (crimps and connectors) was the critical issue in the failure of hoses. You seem to be saying that the length of the hose is the leading cause of failure. Can you cite a source to support this assertion? It could add an interesting dimension to the argument.

I was also thinking about the scenario I sketched yesterday. You sound like a commited HUB user so lets just accept that and approach risk management from the point of view of a HUB. The main issues that keep coming back are the possibility of a dangerous failure do to the hose routing/splitting and the location of the octopus in the pocket causing problems with an OOA buddy. How could you manage these issues? For one thing, you might consider removing the octopus from the pocket and mounting it on a different 1st stage port to wear around your neck on a necklace. This would help reduce the risk of a silmultaneous failure of both your octopus and your main reg because you're now running your octo off of a different port. It would also give you a way to draw breath (and/or to orally fill your BCD) if you blew a main hose and it would give you an easily accessible octopus for the case that an OOA buddy grabbed your primary. One simple change, all major issues addressed to some extent.

But you could go further along these lines because you still have a elevated risk of a hose failure and air loss. To put you in a position to isolate the HUB from the octopus you could put the octopus on a redundant 1st stage and mount the HUB on a tank with a Y valve to fit both 1sts. A good Y valve will also let you shut down the regs independently so you can avoid losing all your air if you blow a hose. Doing this would allow you to turn off the gas to your HUB if you blow a hose while still giving you access to a working reg. Getting *this* setup to totally melt down would require the simultaneous failure of two completely redundant regs. The only single point of failure left in the system is the tank O-ring and you can't do anything about that unless you go to doubles.

These are pretty small modifications that would, if you ask me, improve your safety (reduce your risk) by a considerable margin. Y-valves are about $60, removing the octopus from your pocket and mounting it on a redundant 1st, is probably about $100 including new hoses. Total work about 2 hours. The DIR hardcore will probably call me names for this post but I wanted to show you that risk management isn't just for tekkies and that even without replacing the HUB there are some things you can do to make your kit safer.

R..

 

[Ian Wigg]

Diver0001 once bubbled...


Hi Ian,

I'm saying that I don't think it's easy to check the regulator hoses, especially the hidden bits behind your back. The joint behind your back is critical and should be checked before every dive (just like the one in your pocket) but I'm not convinced that most HUB owners are even aware of this. Many may also not feel the need to check them, just as many divers with traditional kit don't check their hoses regularly. The difference with teh HUB is that failing hoses stand a better chance of going unnoticed because they're out of sight. It's not a cheap jab. I'm more straightforward than that.

Comment was more tongue in cheek than anything!!


I'm interested in the statistics you mentioned. I've always assumed that the number of connection points (crimps and connectors) was the critical issue in the failure of hoses. You seem to be saying that the length of the hose is the leading cause of failure. Can you cite a source to support this assertion? It could add an interesting dimension to the argument.

Not quite - what I am saying is that the MTTF of the hose (as a component rather than the system, if you like i.e. hose + connectors + o-rings) increases exponentially with linear increases in length. The connection points would still remain the main potential failure points however, if the number/type of connections is constant then in a given application a longer hose will be statistically much more liable to failure. As I said, I'll try and dig out the stats.

I was also thinking about the scenario I sketched yesterday. You sound like a commited HUB user so lets just accept that and approach risk management from the point of view of a HUB...

A very interesting suggestion which I'm going to give some serious consideration to - Ta


Ian

R..

 

[tarnis]

Ok, this is somewhat of a different can of works then I've seen open Dive store down here in Florida is selling the Mares Century/Dacor hub for $500...seems like a darned good deal I think.

I have really no equipment just a mask, and fins and stuff. Is this something that'll get me by for the few dives a year I'll be doing with it(once a month or so in the spring/summer)... and if it does have the issues with everything leading into a single hose which I've read, is this something I can just buy for now and then buy some hoses and a new BC later to use the regulator with?

To tack on another question...they only had the Dacor with Viper regulators in my size, not the Mares branded ones. Dacor still worth buying, or are these just going to get phased out like the old regulator someone gave me and I can't use?

thanks,
Matt