I used a SRP air mask and an open face bell boat racing helmet..........Ive seen some guys with a mask under a full face helmet? Not a sealed air tight helmet design, just a normal full face helmet with a mask under it and some of the mask straps coming out of the eye / visor opening and clicking with bayonets to the side of the helmet? Does that set up work? It would seem that you wouldnt be able to get a good fit with the air mask.