This spell is an effort to breath underwater using Aurum/Aquam (and avoid the MuCo(An) canon solution).
Bubble of Air
ReAu(Aq) 15
Forms a bubble of the existing air around the caster's head which she can then breath (assuming the original air is good to breath), regardless of quality or presence of outer air. Can work under water, or in areas of gas or smoke. Can also create a moveable globe-sample of a captured gas or liquid.
(Base 2, +1 Touch, +2 Sun, Individual, +1 Re Req, +1 complexity)(The complexity is in part a balancing factor, because of the flexibilty of this effect - that's not the issue.)
The question is - Would it be possible to cast this on another person, to allow them to have a Hermetic deep-see helmet as well? It could be cast, but then how would the spell effect be attached to that target, to move around with them? (Short of Tethered effects). If they stayed within sight of the caster, perhaps - but technically she'd have to move the effect around as they moved - impractical at best.
(For those new to the system, "the target" of this spell is the Air/Water that forms the bubble, not the person it surrounds. So the Bubble has to be controlled, and another person is only accidentally in the equation.)
I guess my question may be more theoretical, whether this sort of "second hand" effect is even possible, and/or how it would be achieved.
Also whether the air would get "stale", as approp to the recent AM concept of natural law. (Not hard to add a Creo requisite, but if it's not necessary...)
(Also, for those who may not know, I tend to stay fairly close to canon/RAW on my spells - so advice to "just wing it" isn't what I'm looking for, thanks anyway. If I just wanted to do that, I wouldn't ask.) 8)