It is an exciting life controlling a sport he fell in love with at the age of 11.
Ice hockey has taken him to Australia, Mexico, Canada, Hungary, Taiwan and countless other countries along the way just to get to the events.
The journey began in 1994 when he watched a National Hockey League game on Sky television.
"I caught 'hockey fever' when I watched the star Russian player Pavel Bure," he said.
He has been officiating since 1999 and is now involved in his seventh international tournament as a linesman.
"I am usually only assigned one international tournament each year," he said. "But I am normally involved with international travelling teams in New Zealand."
There are eight officials in Dunedin this week from Australia, United Kingdom, Korea, Denmark, Slovakia, France, New Zealand and the supervisor from Germany.
The job of an international official is not only on the ice.
Cairns has daily meetings, on ice sessions, including speed and agility testing, and other roles such as stand-by referee duty, goal judging and post match game and performance reviews.
It is not easy.
"A player will be substituted after only a few minutes but the referee will spend the whole game on the ice and most of it using other skating skills like skating backwards," Cairns said.
"You have to be much faster than the players and also react faster to different situations. A referee trains as hard as the top players to stay on top.
"As an official you have to cope with the speed of the game and pressures from the crowd, players and coaches, " Cairns said.
"You have to control your own emotions as well as trying to control the players. It is very challenging being an official."
Cairns works as an industrial programmer in his day job. He also has family commitments. His wife Nicole gave birth to their daughter Natalie a year ago.
"Natalie was born 10 days before the disastrous February earthquake that all but destroyed Saint George's Hospital," he said.
His own house has withstood the barrage and dreaded liquefaction.
Ice hockey has also suffered in Christchurch.
"Our only ice rink has been spared damage but has to close with each significant earthquake due to power and water damage."
Ryan Cairns
At a glance
• Ryan Cairn's international tournaments.-
2005, Mexico City under 20 division 3 championships; 2006, world men's division 2, Auckland; 2007, under 18 division 2, Hungary; 2008, world men division 2, Newcastle, Australia; 2009, world mens division 3 Dunedin; 2010 under 18 division in Taipei city, Taiwan; 2012, Division 3 under 20 tournament, Dunedin.
• In a match that pitted highest ranked Iceland against lowest ranked Bulgaria, the result was never really in question, Iceland winning the match 10-0. The game started off as expected with Iceland scoring 30sec in, but through some impressive defensive and goaltending from Bulgaria, the winning margin was not as wide as many had been picking.
The match saw the Iceland team toying with the Bulgarians, cycling the puck around seemingly at will, and getting plenty of scoring opportunities (65 shots), while the Bulgarians had to fight for the few opportunities that came their way (12 shots). Halfway through the match the Bulgarians switched goaltenders in what seemed like a pre-planned move to cope with the large number of shots. Great performances from both Bulgarian goaltenders Nikola Nikalov (six goals from 39 shots) and Radosvet Petrov (4 goals from 26 shots) kept the score down.
• Iceland 10 (Gunnar Sigurdsson (3), Brynjar Bergman, Bjorn Sigurdsson , Olafur Olafsson, Steindor Ingason, Olafur Bjornsson, Gunnlaugur Gudmundsson, Sigurdur Reynisson), Bulgaria 0.
