Ask a new surfer what makes a good day and they'll say height. Ask a local and they'll say period. Here's why the locals are right.

Height is drama

Wave height tells you how big. But two feet at a 15-second period is a real swell — organised energy that's travelled thousands of miles. Two feet at a 6-second period is wind chop.

Period is quality

Long period means the energy is stacked deep. When it hits your break, it wraps and peels instead of crumbling. The wave is the same height but it's a completely different ride.