2airishuman
Contributor
Questions on Air2s come up and having now actually talked to people who dive them I think I would like to encourage an honest discussion of their benefits and drawbacks. While the Air2 itself is a Scubapro product, and Scubapro was a pioneer in this area, most of the discussion applies to other brands.
Why an Air2?
The Air2 is sold as an alternative to the octopus. It offers the benefits of primary donate, among them, that the OOA diver receives a known good regulator, the donated regulator is always in the same place (i.e. the diver's mouth) rather than somewhere in the "golden triangle," and the trained response to an OOA diver more closely matches real-world emergencies ("muggings for air").
Most recreational divers are unaware that there is such a configuration as a secondary on a neck bungee, and few instructors and dive shops teach, sell, or rent these configurations, unless they are shops catering to technical divers. Many criticisms of the Air2 made on SB are made in comparison to this configuration rather than in comparison to an octopus.
It's a package deal
Scubapro has, as far as I can tell, only sold Air2s in conjunction with BCs that have a right shoulder dump. Divers who are trained on an Air2 are typically taught to use the right shoulder dump to control their ascent instead of using the exhaust button on the Air2. This is important because the Air2 can't be used as a regulator while the exhaust button is depressed -- it functions just like a power inflator with the exhaust button depressed so that you can inflate the BC orally if necessary.
When using an Air2 on a BC without a shoulder dump during an air sharing ascent, the donating diver has to remove the Air2 from his or her mouth to vent the BC. For accomplished divers this should be no big deal. For novices who aren't comfortable removing the reg from their mouth, well, the intended configuration is to have a BC with shoulder dumps, and they should stick to that or an octo until they are more skilled.
Compared to a secondary on a neck bungee
All but a handful of my dives have been with a secondary under my chin. I went through the process of being a student diver and then a new diver with that configuration. My daughters now dive this configuration and I've watched them.
The Air2 has several advantages:
1) The bungeed secondary adds extra last-minute gear donning steps before entering the water. It's necessary to check the hose routing to make sure it's not twisted with the primary, and then put on the neck strap. Order is important, you have to put on the neck strap after pulling up your hood and before putting on your mask or putting the primary in your mouth. Especially on a boat, where it is a goal to get into the water quickly, this adds an unwanted albeit brief delay. And especially with new divers, it's one more thing to remember.
2) In some circumstances, the bungeed secondary gets in the way. This is particularly true for divers of smaller overall body size or with shorter necks.
3) For bungeed secondaries, hose length and bungee length are diver specific and have to be determined by trial and error. This is one reason you'll probably never see this configuration in rental gear.
4) You can only bungee one regulator. An Air2 opens up the possibility of using the under-the-chin regulator for a back-mounted pony.
And several disadvantages:
1) Though suitable for an immediate ascent, breathing from an Air2 isn't as comfortable as breathing from the primary reg. The bulky hoses limit range of motion and will tend to push on your mouth, and the "inflate" button ends up in an awkward place. Though not a problem on a recreational dive, this poses obvious problems in an overhead environment or in restrictions.
2) LP hose connector compatibility. The oversized connector that the Air2 requires isn't compatible with the fill connector on lift bags or SMBs. When mismatched connectors are used, it's possible for the LP hose connector to jam in the open position leading to a rapid loss of air.
3) The Air2 is more bulky than a standard power inflator, which clutters up the left side of the diver's chest, particularly a problem when carrying a stage or a camera in this area.
4) Difficulties switching BCs. If your regulator set is configured for an Air2, you have to use a BC with an Air2. In the event you need to rent or borrow a BC without an Air2, you have to get a matching regulator set or replace the power inflator on the new BC with the Air2 from your BC.
5) In the event of a stuck inflate valve, it is necessary to disconnect the LP hose from the Air2. This is more difficult to do than it is to disconnect a standard LP hose, because more force is required.
6) There do not appear to be any high-quality integrated inflators on the market, for which parts are readily available for people who service their own gear.
Urban legends and myths
Let it never be said that SB posters lack imagination. Here are some facts to counter the myths
1) Contrary to the myth, high quality integrated inflators breath extremely well (Some early production Air2s did not, and there are reportedly some inexpensive generic knockoffs that do not), comparable to any other regulator at recreational depths. The internal mechanism, diaphragm size, venturi effect, etc., is very similar to ordinary regulators.
2) Contrary to the myth, any of these configurations can be well streamlined. Or be a dangley mess. You have to choose suitable hose lengths and have a means of holding everything in place.
My choices
I have an Air2 that came with a BC I bought used for one of my kids. I replaced it with a K inflator so that we could all dive the same configuration.
Then on a dark and stormy night in a back alley behind a dive shop in Key Largo, I met with a fellow, who after carefully checking to be sure neither one of us had been followed by a ScubaPro manufacturer's representative, sold me a service kit for it. I serviced it, but it's only been wet when I was adjusting it using the kitchen sink-a-helic gauge.
I like my ordinary K inflators and bungeed secondaries because it is what we are all used to. All the parts interchange, all the regs work with all the BCs, I don't have to visit dark alleys to get service kits, and I have room for my stage bottle on my left side.
I have some friends who dive Air2s who are safe and streamlined, and this weekend we're going to go blow bubbles together without dissing each others' gear choices.
Why an Air2?
The Air2 is sold as an alternative to the octopus. It offers the benefits of primary donate, among them, that the OOA diver receives a known good regulator, the donated regulator is always in the same place (i.e. the diver's mouth) rather than somewhere in the "golden triangle," and the trained response to an OOA diver more closely matches real-world emergencies ("muggings for air").
Most recreational divers are unaware that there is such a configuration as a secondary on a neck bungee, and few instructors and dive shops teach, sell, or rent these configurations, unless they are shops catering to technical divers. Many criticisms of the Air2 made on SB are made in comparison to this configuration rather than in comparison to an octopus.
It's a package deal
Scubapro has, as far as I can tell, only sold Air2s in conjunction with BCs that have a right shoulder dump. Divers who are trained on an Air2 are typically taught to use the right shoulder dump to control their ascent instead of using the exhaust button on the Air2. This is important because the Air2 can't be used as a regulator while the exhaust button is depressed -- it functions just like a power inflator with the exhaust button depressed so that you can inflate the BC orally if necessary.
When using an Air2 on a BC without a shoulder dump during an air sharing ascent, the donating diver has to remove the Air2 from his or her mouth to vent the BC. For accomplished divers this should be no big deal. For novices who aren't comfortable removing the reg from their mouth, well, the intended configuration is to have a BC with shoulder dumps, and they should stick to that or an octo until they are more skilled.
Compared to a secondary on a neck bungee
All but a handful of my dives have been with a secondary under my chin. I went through the process of being a student diver and then a new diver with that configuration. My daughters now dive this configuration and I've watched them.
The Air2 has several advantages:
1) The bungeed secondary adds extra last-minute gear donning steps before entering the water. It's necessary to check the hose routing to make sure it's not twisted with the primary, and then put on the neck strap. Order is important, you have to put on the neck strap after pulling up your hood and before putting on your mask or putting the primary in your mouth. Especially on a boat, where it is a goal to get into the water quickly, this adds an unwanted albeit brief delay. And especially with new divers, it's one more thing to remember.
2) In some circumstances, the bungeed secondary gets in the way. This is particularly true for divers of smaller overall body size or with shorter necks.
3) For bungeed secondaries, hose length and bungee length are diver specific and have to be determined by trial and error. This is one reason you'll probably never see this configuration in rental gear.
4) You can only bungee one regulator. An Air2 opens up the possibility of using the under-the-chin regulator for a back-mounted pony.
And several disadvantages:
1) Though suitable for an immediate ascent, breathing from an Air2 isn't as comfortable as breathing from the primary reg. The bulky hoses limit range of motion and will tend to push on your mouth, and the "inflate" button ends up in an awkward place. Though not a problem on a recreational dive, this poses obvious problems in an overhead environment or in restrictions.
2) LP hose connector compatibility. The oversized connector that the Air2 requires isn't compatible with the fill connector on lift bags or SMBs. When mismatched connectors are used, it's possible for the LP hose connector to jam in the open position leading to a rapid loss of air.
3) The Air2 is more bulky than a standard power inflator, which clutters up the left side of the diver's chest, particularly a problem when carrying a stage or a camera in this area.
4) Difficulties switching BCs. If your regulator set is configured for an Air2, you have to use a BC with an Air2. In the event you need to rent or borrow a BC without an Air2, you have to get a matching regulator set or replace the power inflator on the new BC with the Air2 from your BC.
5) In the event of a stuck inflate valve, it is necessary to disconnect the LP hose from the Air2. This is more difficult to do than it is to disconnect a standard LP hose, because more force is required.
6) There do not appear to be any high-quality integrated inflators on the market, for which parts are readily available for people who service their own gear.
Urban legends and myths
Let it never be said that SB posters lack imagination. Here are some facts to counter the myths
1) Contrary to the myth, high quality integrated inflators breath extremely well (Some early production Air2s did not, and there are reportedly some inexpensive generic knockoffs that do not), comparable to any other regulator at recreational depths. The internal mechanism, diaphragm size, venturi effect, etc., is very similar to ordinary regulators.
2) Contrary to the myth, any of these configurations can be well streamlined. Or be a dangley mess. You have to choose suitable hose lengths and have a means of holding everything in place.
My choices
I have an Air2 that came with a BC I bought used for one of my kids. I replaced it with a K inflator so that we could all dive the same configuration.
Then on a dark and stormy night in a back alley behind a dive shop in Key Largo, I met with a fellow, who after carefully checking to be sure neither one of us had been followed by a ScubaPro manufacturer's representative, sold me a service kit for it. I serviced it, but it's only been wet when I was adjusting it using the kitchen sink-a-helic gauge.
I like my ordinary K inflators and bungeed secondaries because it is what we are all used to. All the parts interchange, all the regs work with all the BCs, I don't have to visit dark alleys to get service kits, and I have room for my stage bottle on my left side.
I have some friends who dive Air2s who are safe and streamlined, and this weekend we're going to go blow bubbles together without dissing each others' gear choices.
