New Reg Owner question

[shugar]

I just got a new Scubapro MK2/R290 setup... "got" not "bought"

question is: do i have a good reg? what should I expect? it's my first reg and i haven't had a chance to get it wet

I'm a purely tropical recreational diver who hopes to get 25 dives in a year (chances are less :depressed

should i start looking at off-loading the MK2 and/or R290?

thanks in advance

Jag

 

[Sas]

I just got a new Scubapro MK2/R290 setup... "got" not "bought"

question is: do i have a good reg? what should I expect? it's my first reg and i haven't had a chance to get it wet

I'm a purely tropical recreational diver who hopes to get 25 dives in a year (chances are less :depressed

should i start looking at off-loading the MK2 and/or R290?

thanks in advance

Jag

The shop I rented gear from for a while early on when I started diving had this set up. I found below 20 or so metres it did not breathe well and I would get headaches. I bought an MK11/S555 and have had no issues with that one. However, ymmv as I don't know if I was just unlucky with the regs I hired or whether the reg just isn't that great for deeper diving.

All that being said, I would think if you are only going to do 25 dives a year then it should be fine. I really doubt it is worthwhile to buy a more expensive one in your case! I personally wouldn't bother to buy a reg setup if I was going to do <25 dives a year and would just rent instead (or stick with the MK2/R290).

 

[shugar]

yeah... my friend at the diveshop said that would be caused by the 1st stage being "unbalanced"...

would getting a new 1st stage later on help?

Jag

 

[tstormdiver]

The MK2/R290 is at the bottom tier of Scubapro's regulator line up. I am not saying it is a bad regulator so much,.... it just depends on what you plan to do. It is an unbalanced regulator, meaning that it will become harder to breathe on as you go deeper or the air pressure becomes less in the tank, unlike balanced regulators which give the same amount of air regardless of depth or pressure in the tank (unless it goes empty, which, of course we know will never happen). That said, though, a lower end regulator tends to be quite the workhorse with fewer potential problems because it is of a much simpler build. What type of regulator you want depends on what kind of diving you want to do, not how many dives. If you plan on only easy, warm water, shallow dives, then that regulator may serve you well. If you plan for a bit more advanced dives, then perhaps you may want to consider something a tad more advanced. I personally own 4 Scubapro MK25/S600's while yes, they are quite expensive, I know they will deliver the air I demand from them, as I pursue technical diving. As with almost anything, there are downsides to everything. Where the MK25/S600 will give me the air I demand, because of this trait, that regulator has the tendency to freeze up & free flow (I know, I recently had it happen to me at 90 ft- not much fun) as I tend to dive in cold dark quarries year round. With everything you gain, there is usually also something that must be given up. You must decide what you want. There is plenty of research material & resources out there, do your homework. You may even tap your instructor or LDS for information. Just listen to what they have to say. Ask questions. Don't immediately buy from them just because of the sales pitch. Like I said , listen to them, the corroborate what they say, with known facts on the product. If you can, try out a few different kinds of regulators to see what you like. Get to know the good, the bad & the ugly of the regulator type you're looking for. When I started diving, I bought the bottom of the line regulators. I found for me, personally, it was not enough for what I wanted to do. I then upgraded & found that the upgrade STILL wasn't enough for what I wanted. & wound up having to buy a 3rd round of regulators before I found one I liked. If I had just done my homework better, I might have just had to buy 1 set of regulators instead of 3 to find what I like.

 

[DA Aquamaster]

The Mk 2 is adequate for recreational diving to 130 ft or so. But yes, the unbalanced flow by first stage tends to have a smaller orifice that reduces air flow to around 90 SCFM compared to maybe 150 for a "high performance" second stage. But to put that in perspective the best second stage available only flows about 65 SCFM and the R290 probably flows about 50 SCFM.

So with the Mk 2 R290, the limiting factor is not the first stage as much as it is the second stage. But to again put this in perspective, no one breathes 50 SCFM under normal circumstances. At 130 feet with a large consumption rate of even 1.0 cu ft per minute, you are only breathing 5 cu ft per minute, and the reg can theoretically deliver that in 6 seconds. Assuming you inhale 6 times per minute when working hard, you'd have to inhale in less than 1 second to out breathe the reg. Can it be done? Absolutely, but you will be very anxious or working very hard to do it. On a normal recreational dive you should not encounter a need to breathe more than a Mk 2 R290 can deliver.

The real issue is often the work of breathing. A higher inhalation effort can lead to more CO2 retention and make you feel you are not getting enough air. Most R290's can be made to breathe quite well but most don't come that was from the factory as the specs are pretty wide (1.2 to 1.4" of water with an upper limit of 1.8" for an octo). Have your LDS check the IP to ensure it is at 145 psi with a 3000 psi supply presure and then have your LDS check the second stage and tune it for an inhalation effort of 1.2" of water - the low end of the specification - and have them set the flow vane or maximum venturi assist. All three will improve how the reg breathes.

If you ensure the reg is performing properly, the odds are much greater you will be satisfied with it, particularly on tropical/recreational dives. It's light weight makes it a good travel reg as well.

If you get into technical diving and need more gas, the Mk 17 is a great choice - I prefer it to the Mk 25 as the Mk 25 has a bad case of overkill combined with poor cold water performance.

There is also a qualitative difference in regs. I have long been spoiled by Scubapro's balanced second stages and the difference is not so much flow rate as it is smoothness of the airflow. In general once you go forward and step un in a reg class, you can't go backward and be happy.

 

[beanojones]

I'll buy trade the first stage for a Aqualung Cousteau SEA first stage straight up.

Then you would have a better performing first stage, and I would have a rental Mk2.

(DAAM, was it you that pointed out that SP 'should' mix their first and second stages the other way, like a g250 with a mk2, instead of a r190 with a Mk15? I dove with that combo (G250/mk2) many, many dives.)