scuba adapter/ stock?

is it possible to have stock on the gun with no tank but a hose with a type of valve to hook up to a scuba tank for shooting at the range or something rather than just keep filling the regular tank?
i dont know if this has been explored befor. i would think if you could hook up your scuba tank like you do a backpack tank for paintballs you would beable to get alot of consistant shots. just doing some thinking here