Arrambide's long-awaited QS win came on home soil with huge performances over event standouts throughout finals day.
The QS1,000 got off to a dreamy start at Southside HB Pier with top seeds dominating the lineup.
The men's QS1000 ripped through Round 4 of action and are set to compete in one-on-one competition.
The region's best surfers continued to post near-perfect scores in more East Coast windswell that provided plenty of opportunity.
Past champions, international standouts and local heroes headline this year's Coldwater Classic at Santa Cruz's Steamer Lane.
International field battles in Huntington Beach to start the 2015 WSL season.
O'Neill confirms competitor list for 2014 Coldwater Classic Invitational
Elite Tour hopefuls went to battle in peaky conditions at Surf City.
Final four spots in Vans US Open of Surfing Prime-rated Men's event are decided in final trials.
First day of competition greets the world's top surfers with pumping conditions.