The cash prize, from a pot of $250 courtesy of NZONE Skydive, will be awarded to the best overall skater, as judged by three elite skaters, by the close of play at the skate park on Saturday. The remaining $50 and a new skate deck will be presented to the bowl competition winner.
Skate gear and decks will be up for grabs for more challenges, including an ollie competition.
The session is divided into under-16 and over-16 age groups, with first, second and third places in both.
Youth bands supported by the RockFormation Charitable Trust, including the Collective Me, and DJs are lined-up to provide the soundtrack.
Radio presenter Henry Youngman will be master of ceremonies. Hundreds of spectators attend each annual Summer Sk8 Sesh and a sausage sizzle will be running.
''It will be an awesome event,'' Youth Booth youth worker Fi Sawers said.
''Skaters from all over the South Island will show some incredible tricks, techniques and styles.
''It's an event for all, novices through to pros, and non-skaters will enjoy the day.''
Registrations open at 10am at the park. Open entry costs $10 and under-16 entry costs $5.
Prizegiving was expected to be held about 4pm.