And that passion took the 16-year-old St Kevin's College pupil to Germany last month where she claimed third place in the junior division at the World Cup.
The event was held on the Eiskanal - a long way from Kakanui beach where she honed her craft - and was the world's first artificial kayaking course, constructed for the 1972 Olympics.
In freestyle kayaking, competitors score points by performing stunts on rough water.
"You've got 45 seconds to get as many points as you can," Kerin said.
"[The tricks] have all got funky names which people have probably never heard of, like spins, loops, cartwheels, space godzillas ...".
Space godzillas?
"It's a twisted loop."
Courtney said the water feature on the Eiskanal was extremely challenging and took some competitors by surprise, including some of the men.
"It wasn't a very high-scoring event because the feature was very powerful. But I managed to pull it off."
The World Cup is held every two years, with the world championships on the alternate years.
The second event of the 2010 World Cup was cancelled due to flooding, which meant Kerin claimed third place behind two European paddlers.
It was her first experience of competing internationally.
Locally, she won the 2009 Bliss-Fest surf competition in Dunedin last October and plans to return to defend her title this year.
Kerin can compete as a junior at the world championships next year and will chase the gold medal.
