That is an interesting path from being completely new in diving, then to learn diving in warm water come to ice diving. Respect! I can't imagine myself in such cold underwater. I love winter with its minus degrees and as a child we lived there where winter had -20-25C, with a lot of snow. I love to be outside but ice cold water, no...not for me. You made it right to have Russian instructors they know how the environment there and they have their tricks and tips too. I believe all these requires a lot of energy and of course you body boosts adrenaline that made your very satisfied and I would even say drunk from happiness. Absolutely heroic hobby. Really interesting article and beautiful photographs :)