Russian scuba divers took merriment to extreme temperatures on Sunday, when they placed a Christmas tree on the bottom of the freezing cold Blue Lake in Kazan. A group of six divers lowered the mini-Christmas tree, complete with decorations, 10 metres to the lake floor. The occasion clearly merited a toast and footage shows divers drinking from a bottle of champagne. The Bentos diving club at... Еще the Kazan State Medical University is the organisation behind this unique festive tradition. Christmas in Russia is celebrated on 7th January, in accordance with the Julian calendar used by the Orthodox Church.