1. Long hose twice around the neck -- bad deal -- I'd strongly advise against this.
2. I am not an Air2 fan but have done a number of dives with them. I do not see any good reason to add swivels for sharing - just S the hose.
3. I personally prefer to have a real regulator for emergencies. I dive with either a standard config (teaching), or with a long hose / necklace (diving).
4. The Primary, Octo, and Air2 for teaching is a fine idea. A number of our instructors use this configuration.
2. I am not an Air2 fan but have done a number of dives with them. I do not see any good reason to add swivels for sharing - just S the hose.
3. I personally prefer to have a real regulator for emergencies. I dive with either a standard config (teaching), or with a long hose / necklace (diving).
4. The Primary, Octo, and Air2 for teaching is a fine idea. A number of our instructors use this configuration.