Margaret River (Main Break) Alert Guide

Western Australia, Australia · part of the Margaret River (Main Break) spot guide

Margaret River is forecast-only — the nearest NDBC buoy is roughly 4,500 km away, with the regional Cape Naturaliste waverider as an in-situ cross-check. The height below is an open-ocean reading; the point focuses long-period energy so the face runs larger. White sharks are a factual regional consideration here — heed local advisories and beach closures.

The forecaster's checklist

1. 1.Want swell from the southwest to west-southwest (core about 210–250°); south-southwest brings the maximum Southern Ocean juice, west and west-northwest still work but are often windier.
2. 2.Period is the key gate — target 15-to-16 seconds or more of long-period groundswell; short-period windswell is weaker and junkier.
3. 3.Open-ocean height around 5 feet turns it on; roughly 8-foot-plus at 15 seconds is maxing Main Break and outer-Bombie territory.
4. 4.Score an east or southeast offshore at dawn before the sea breeze; the classic setup is a west-southwest swell with an easterly.
5. 5.Respect the power, the shallow reef and shark advisories at size — this is not a beginner break.

Local winds & tide

Best wind: E–SE offshore — from 45° to 160° (NE–SSE).

Micro-tidal, so tide is a minor factor and Main Break works across it; the shallowest lows expose more of the inside and Box reef and add hazard.

Dial it in