Everything surfing.

Almost every wave you'll ever ride started as wind. When wind blows over open ocean it drags energy into the water, building a chaotic, choppy sea. The distance and duration that wind blows over is called the fetch — a bigger fetch makes bigger, more organised swell.

As that energy leaves the storm, it sorts itself into orderly lines and becomes swell: pulses of energy travelling across the ocean, sometimes for thousands of kilometres, long after the wind that made them has gone.

A forecast — like the live report on every spot page here — comes down to four things. Wave height is the raw swell size. Swell period is the seconds between waves: under 8s is weak windswell, 14s+ is powerful groundswell. Wind decides whether the surface is clean or ruined. Tide changes the depth over the break.

The trick is reading them together. Two metres at 15 seconds is a serious, powerful day; two metres at 6 seconds is soft and gutless. Same height, completely different surf.

Tides are the slow rise and fall of sea level caused by the moon and sun, cycling roughly every six hours between high and low. For surfers, the tide matters because it changes the depth of water over the reef or sandbar the wave breaks on.

Too much water and a wave goes fat and lazy; too little and it breaks straight onto dry rock. Most spots have a tide window where they're at their best.

The bottom a wave breaks over shapes how it behaves. A beach break breaks over shifting sand — changeable, forgiving, where most people learn. A point break wraps around a headland and peels in one long direction, giving the longest rides in surfing.

A reef break forms over fixed rock or coral: consistent and hollow, but shallow. A slab is a reef wave that leaps up over a sudden ledge into a thick, square barrel — the heaviest of the lot. And big-wave spots break far offshore over deep reefs, only waking up on giant swells.

A shortboard is thin and nimble, built for steep, powerful waves and high-performance surfing — but hard to paddle. A longboard is the opposite: long, floaty and stable, made for gliding and noseriding on softer waves, and the classic board to learn on.

In between sit the fish — short, wide and fast for small, weak surf — and the gun, a long, narrow board built purely to paddle into big waves. A full 'quiver' covers every condition.

Surfing has one golden rule: the surfer closest to the breaking peak has priority, and everyone else stays off that wave. Taking off in front of someone who has priority is 'dropping in' — the cardinal sin, dangerous and the fastest way to start trouble.

Respect the pecking order, wait your turn, don't paddle straight to the peak, and apologise if you blow it. Localism eases when you show you know the rules.