Pipeline Alert Guide

Hawaii, USA · part of the Pipeline spot guide

Because the Waimea buoy sits only about seven kilometres off the same coastline and is the gauge North Shore forecasters read directly, a live-observation alert is a sound trigger here — when it actually reads the right height, period and direction, Pipe is breaking.

The forecaster's checklist

1. 1.Watch for a strong North Pacific / Aleutian low with a long fetch aimed at Hawaii, ideally delivering swell from the WNW around 290–330°.
2. 2.Use the buoy relay for lead time: deep-ocean 51101 (NW Hawaii) registers the swell first, then it reaches 51201 at Waimea, then the beach fills in behind.
3. 3.Read 51201 for the classic-Pipe signature: roughly 4–8 ft significant height at 14 seconds or longer from the WNW.
4. 4.Mind the direction: too far west and Backdoor walls up while the Pipe left dominates; too far north and the reef is partly shadowed and loses its clean refraction.
5. 5.Time the wind and tide — a light offshore from the south or southeast and a low-to-mid tide make it hollowest, which is why dawn before the trades fill is prized.

Local winds & tide

Best wind: S–SE offshore (a passing front); NE trades blow side-offshore — from 135° to 210° (SE–SSW).

Pipeline is best on a low-to-mid tide, roughly -1 to +1 ft: the reef sits shallower, the wave jacks harder and the barrel pitches further. High tide fattens it.

Dial it in