Best regs with scubapro AIR-2?

[Wolfbane]

Hi there,
This is my first post and have only been diving since for a few months, with 18 dives logged and just got my advanced OW.
So far I have hired gear whilst diving in Melbourne waters.

I have decided to now buy the Scubapro Knighthawk BCD and like the idea of the AIR-2 for streamlining. However, I am stuck on what regs to go for. I really want to get something decent & reliable whilst having the flexibility to handle deep dives (if I do the courses).

Having said that, I have heard that their can be a problem with freeflow on the AIR-2 if used with quality regs like Apeks, due to the "over balance" feature. I wondered what other people use with the AIR-2 and what its limitations may be with depth & temp depending on what regs are used with it?

Thanks for any imput you guys can give me on this.

 

[jeadiver]

Having said that, I have heard that their can be a problem with freeflow on the AIR-2 if used with quality regs like Apeks, due to the "over balance" feature. I wondered what other people use with the AIR-2 and what its limitations may be with depth & temp depending on what regs are used with it?

I have used an Air2 with a Sherwood Magnum and know folks who have used it with an Atomic. Never known of a significant freeflow problem.

 

[erikharwell]

go with a real octo.

 

[greyface]

ScubaPro Mk16/R390

 

[SamDiver14]

If you really like the idea of having a secondary air source (non redundant) on your inflator hose look at the slimline inline by Oceanic. It functions the same as the Air2 but if the inflator mechanism fails you don't lose your secondary air source. The inline can be disconnected and used alone and then you can orally inflate. The biggest problem with the integrated octo is that a inflator failure can cost you your secondary air source. Is that a risk you want to run just to streamline a little? But that is why the Oceanic deal works well, you can get it all in the same package. I had the slimline setup for a while, but the fact is I just didn't like it. It was uncomfortable and a pain to use. So I just went back to a regular octopus and arrange the hoses to minimize drag.

 

[archman]

My AIR 2's been hooked up to a trusty 'ol MK2+ for years, never a worry.

Ideally you should keep your regulators all on the same page regarding their manufacture. So if you have an AIR 2, try to stick with ScubaPro 1st and 2nd stages, or at least the first stage. Your servicing technician will be happier for it.

 

[nwdiver2]

The shadow by Sherwood has the same capabilities as the slimline inline by Oceanic. They are good alternatives to the Air2.

 

[love2godeep]

I use a Scubapro MK25/S550 with my AIR2, and they work beautifully together.

I tried breathing off my AIR2 for a good share of one dive, and it worked great; just the mouthpiece was a little large for me.

 

[IslandHopper]

My Air2 has NEVER freeflowed (on a Mk16 1st).

I Love the Air2 for my rec dives ... but since I have gotten into deep/tech diving I am going to go to a "normal" set up. (In fact, I think I'll do a Hogarthian setup for my hoses/regs).

If you plan to get into deco or other tec diving, you may want a regular octo, as they allow more freedom of movement when you are using them (not a big deal when you're just gonna use it to surface, but if you have a deco obligation, 20-30 minutes will be more comfortable with a regular octo.)

 

[DA Aquamaster]

Having said that, I have heard that their can be a problem with freeflow on the AIR-2 if used with quality regs like Apeks, due to the "over balance" feature.

Over balancing in it most accurate form means that the reg is designed to give a slight increase in intermediate pressure as tank pressure decreases. In a piston first stage this is done by substantially reducing the piston stem diameter compared to the knife edge diameter on the piston. There is however no real advantage to doing this beyond a very finite point.

To have a totally balanced design with a unchanging IP, a piston reg actually has to be constructed slightly over balanced. This small amont of over balancing is needed to account for the area of the knife edge which even though slight, does represent some surface area for the tank pressue to act upon and slightly change IP as tank pressure decreases. Over balancing slighty to account for this area will result in a truly stable IP that will not change with tank pressure. When this is done, the marketing folks often say it is "over balanced" but "completely balanced" would be a more correct term.

IP also increases as tank pressure decreases with an unbalanced diaphragm piston first stage and increases as tank pressure increases on an unablanced piston first stage. Both of these designs lower cost designs can cause problems with free flow on any finely tuned second stage. It is not however a problem with a properly tuned reg where the final second stage adjustments are made at the tank pressure where maximum IP will occur.

In short an AIR 2 will work fine on just about any reg as long as it is properly adjusted for use with the first stage. This is even less critical with a balanced or over balanced first stage.

I wondered what other people use with the AIR-2 and what its limitations may be with depth & temp depending on what regs are used with it?

I have used mine with Scubapro Mk 10's, 15's, 20's and 25's down to 150' and in temps down to 34 degrees with no concerns. I have also abused it by using it to fill lift bags at 100' and temps down to 39 degrees. When subjected to constant air flows in very cold water it will freeze up eventually (like a regular second stage, but it is easily disconnected (unlike a regular second stage) which is why I prefer it for that particular application.

The business end of the Air 2 uses the same basic design and seat as the R190/R390 with a smaller lever and diaphragm. They are quite reliable and basically bullet proof when properly adjusted.