Best regulator for tech and cave diving?

[NAM001]

To the op

Perhaps the better question might be::::::: What are the quality's of a good tech/cave regulator.
Personally I use Scubapro mk25's and s600's. When I got them, the research I did said they breath with little if any change to 200 ft. That most regs start breathing harder from 100-130ft.

 

[tbone1004]

no, unless the hog is specifically a reversible design the case can not be reversed, it is a completely idiotic decision on Chris and then Jack's part to make a limited production run of reversible seconds and not just move all of the production to the reversible design, but it is what it is. As it stands standard second stages casings are one side and one side only.

 

[halocline]

To the op

Perhaps the better question might be::::::: What are the quality's of a good tech/cave regulator.
Personally I use Scubapro mk25's and s600's. When I got them, the research I did said they breath with little if any change to 200 ft. That most regs start breathing harder from 100-130ft.

Sorry to tell you this, but your "research" sounds more like sales literature. All scuba regulators 1st stages compensate for depth in the same way; by introducing ambient pressure to part of the first stage which then adjusts IP so that it remains a constant over ambient. All 2nd stages compensate for depth in the same way, in fact all 2nd stages will breathe pretty much the same at any reasonable depth. The only thing that changes with the 2nd stage is, eventually the viscosity of the gas introduces a higher friction coefficient, but calculating that is way beyond my understanding, and I'm sure its well beyond anything a reasonable diver would be using air for anyway.

With the 1st stage, the limiting factor is flow rate, and it's true that the MK25 has a monster flow rate. But, as far as providing gas for a single 2nd stage, any decently-performing first stage will more than do the job; consider the fact that most 1st stages have a flow rate that far exceeds the tank valve.

 

[buddhasummer]

Sorry to tell you this, but your "research" sounds more like sales literature. All scuba regulators 1st stages compensate for depth in the same way; by introducing ambient pressure to part of the first stage which then adjusts IP so that it remains a constant over ambient. All 2nd stages compensate for depth in the same way, in fact all 2nd stages will breathe pretty much the same at any reasonable depth. The only thing that changes with the 2nd stage is, eventually the viscosity of the gas introduces a higher friction coefficient, but calculating that is way beyond my understanding, and I'm sure its well beyond anything a reasonable diver would be using air for anyway.

With the 1st stage, the limiting factor is flow rate, and it's true that the MK25 has a monster flow rate. But, as far as providing gas for a single 2nd stage, any decently-performing first stage will more than do the job; consider the fact that most 1st stages have a flow rate that far exceeds the tank valve.

Wow, you sure know your stuff. I'm in awe of your knowledge, seriously. I always enjoy reading your posts about regulators as almost always learn something new, cheers.

 

[victorzamora]

Sorry to tell you this, but your "research" sounds more like sales literature. All scuba regulators 1st stages compensate for depth in the same way; by introducing ambient pressure to part of the first stage which then adjusts IP so that it remains a constant over ambient. All 2nd stages compensate for depth in the same way, in fact all 2nd stages will breathe pretty much the same at any reasonable depth. The only thing that changes with the 2nd stage is, eventually the viscosity of the gas introduces a higher friction coefficient, but calculating that is way beyond my understanding, and I'm sure its well beyond anything a reasonable diver would be using air for anyway.

With the 1st stage, the limiting factor is flow rate, and it's true that the MK25 has a monster flow rate. But, as far as providing gas for a single 2nd stage, any decently-performing first stage will more than do the job; consider the fact that most 1st stages have a flow rate that far exceeds the tank valve.

Thanks for posting this. Saved me the hassle . One thing I will say (to clarify, not correct) is that there are really three ways of compensating for depth. One is to not compensate at all. SUPER rare. The other two are practically built in to the type of first stage: balanced and overbalanced. Balanced is where the first stage is always putting out pressure a fixed amount over the ambient. This is most piston regulators, like the Scubapro regs mentioned. Overbalanced is where the pressure over ambient actually increases with depth, which is what most diaphragm regulators do. The hogs do this. This means they actually can provide more air and breathe better as they go deeper. Negligible, and should be being compensated for with PLENTY of helium, but in theory the Scubapro literature was untrue and unprofessional.

They're not bad regs, but they're certainly not better. Also, I really dislike rebuilding piston regs so I'll never own Scubapro or Atomic regs.

---------- Post added March 1st, 2015 at 11:59 AM ----------

OP: one big consideration not mentioned yet is how often tech divers maintain their own gear. Hog sells parts to consumers. Few other manufacturers do.

 

[halocline]

Overbalanced is where the pressure over ambient actually increases with depth, which is what most diaphragm regulators do. The hogs do this. This means they actually can provide more air and breathe better as they go deeper.

I was going to mention the so-called "overbalanced" regulators, but didn't because it's really nothing more than more sales hype, and here's why. First, though, it's not most diaphragm regulators that are overbalanced, its only a few that have environmental seals. The way they do it is to have a slightly oversized external diaphragm and some sort of rigid transfer piston to the internal diaphragm. Since the surface are of the outer diaphragm is greater, the total pressure increase on it as depth increases is higher and this higher pressure is transferred to the internal diaphragm. This results in slightly higher IP.

The reason this doesn't significantly affect breathing effort is because these type of 1st stages only work with air balanced 2nd stages. (otherwise, the increase in IP could cause a freeflow at depth) And all air balanced 2nd stages use IP to provide the balancing counter-force on the valve. Ergo, as IP goes up, so does cracking effort and vice versa. There is some downstream bias in typical balanced 2nd stages, so not the entire increase in IP is applied to increase cracking pressure, but most of it is.

So the net result is more or less nullified by the 2nd stage. There is some truth, theoretically anyhow, that more pressure in the LP hoses means a great potential flow rate, but as anyone who has seen a LP hose failure underwater knows, there is already PLENTY of flow capacity in those hoses without any assistance from an increased IP over ambient.

 

[SeaCobra]

or tech and cave diving, is price really the primary consideration? You want TOP quality for this type of diving. Apeks and ScubaPro have long set the bar and are the ones that everyone attempts to copy. For me, get the original.

 

[NAM001]

This information was form 2003 in a rodels regulator evaluation article. And i believe it ws generally speeking to air supplied by the first stage as opposed to the second stage. Thier point of the aspect for that comparison was if 2 high demand divers had to share air that the mk25 would supply from normal depths because ther was no single diver deteriation of air supply down to 200 ft. Basically commenting to your comment regarding to the "MONSTER FLOW RATE". In short the reg doesnt max its flow rate till past 200 ft. I do not recall the comments regarding the S600 in that article. The thought I tried to get across was that any reg will give you the air you need as a single diver but if you need to share air that the MK25 will more than handle it. I said that knowing that most likely there would never be 2 on one reg with a tech kit. The other thing about the article was that it implied that the mk25 could take a lot of degredation in performance before impacting the diver. As right or wrong as my comment was per your scrutiny the post is still worthy as to what aspects one should keep in mind when buying equipment of this type. Thank you for your corrections anyway.

Sorry to tell you this, but your "research" sounds more like sales literature. All scuba regulators 1st stages compensate for depth in the same way; by introducing ambient pressure to part of the first stage which then adjusts IP so that it remains a constant over ambient. All 2nd stages compensate for depth in the same way, in fact all 2nd stages will breathe pretty much the same at any reasonable depth. The only thing that changes with the 2nd stage is, eventually the viscosity of the gas introduces a higher friction coefficient, but calculating that is way beyond my understanding, and I'm sure its well beyond anything a reasonable diver would be using air for anyway.

With the 1st stage, the limiting factor is flow rate, and it's true that the MK25 has a monster flow rate. But, as far as providing gas for a single 2nd stage, any decently-performing first stage will more than do the job; consider the fact that most 1st stages have a flow rate that far exceeds the tank valve.

 

[Scuba7]

Hog sells parts to consumers. Few other manufacturers do.

You have a good point.
I was watching a cave diving doco yesterday and some of the scientists were using re-breathers and dive rite gear, so they dont all use Apeks etc.

---------- Post added March 2nd, 2015 at 08:28 AM ----------

or tech and cave diving, is price really the primary consideration? You want TOP quality for this type of diving.

Quality first but being in the business longer does not mean you are better.

Do you drive a Ford because they were one of the first to build cars?
I do but only because they are easy to look after.

 

[tbone1004]

Apeks have been getting phased out of the technical community for a while because parts kits are so hard to come by, same reason you don't see as many Scubapro's as you used to. When the knockoffs became very good quality, especially the Apeks, were half the price to buy, and you could buy the parts yourself without "knowing a guy who knows a guy", their marketshare to the tech market started dwindling.

The quality argument at this point is complete and utter bullsh!t, there's no marked difference in quality among the larger brands, and there is a lot of laurel resting going on at that level, so while price is not the primary consideration it is price/performance/quality, and at this point the Hog/DiveRite/Hollis etc which all come out of ODS are offering a bang up piece of kit for about half the cost of Apeks, so no, price isn't the consideration, but if I have to pay 2x for the Apeks regs, then can't buy the parts to service them myself because they're a bunch of raging cnts that want to pad the pockets of their dealers every two years with cost of service, then they won't get my business and I'll keep supporting the guys that are actually trying to push things forward. It really is a shame because they are putting out real quality stuff, but the price they're charging for it gives you no better quality, no better performance, and the fact that they lock parts kits down to authorized technicians working for an authorized dealer is complete bs *I'm an authorized Apeks tech but can't buy parts kits because I'm not currently employed by one of their dealers, SP is the same way, and there is no reason for it* I wish we had the consumer protection laws that some of the EU has in place where stuff like that would be illegal.

rant over, my apologies Jeff, but that is truly one of the most ignorant statements you can make about scuba gear