This annual fishing tournament challenges anglers to land the heaviest Spanish Mackerel — and to commemorate 100 Years of Onslow, this year’s top prize has doubled to $20,000 thanks to our major event sponsor, Munro's Contracting! A standout on WA’s fishing calendar, the Mack10K is all about big catches, community spirit and fun. Whether you're a seasoned fisher or just love the thrill, this is one event you won't want to miss!