Yesterday we tripped across this video of an Austrian cold water freedivers playing hockey under a frozen lake. It's two years old, but extremely cool. The players use the frozen top of the lake as the rink. Since they're not using oxygen tanks, the players surface for air every 30 seconds or so. Meanwhile, the refs get the luxury of an oxygen tank. We're kind of curious about how players come to fistcuffs or what the penalty box is. It looks like they're going relatively soft on each other, presumably because if bodychecking someone and rupturing their wet suit would result in extreme hypothermia. Check out "under ice hockey" after the jump.

Here's some more under ice hockey footage: