Greymouth spearfishing forecast — wind, swell, visibility, tides & live cameras

Our own model

Our own forecast engine — not a third-party widget. It weighs these water factors into one go-or-stay verdict for this coast; the 0–10 dial is that verdict, read out as a number.

01

Swell & wave memory

Height, period and direction of the swell, plus the wake of recent storms — an old storm still stirs the water, and the engine remembers.

02

Wind & gusts

Speed and gusts, hour by hour — wind speed and an onshore push chop the surface and cut visibility.

03

Tide phase

Timing and range of the tide, calibrated per coast — big spring tides pull the verdict toward caution.

04

Water temperature

Sea-surface temperature — sharply cold water vetoes a green verdict.

05

Currents & outflow

Direction and drift of the current — it pushes you, and it drags turbid coastal water across where you dive.

06

Rain runoff & air clarity

Rain muddies the water inshore through land runoff, while fog and haze cut visibility at the surface.

07

Coast shape & exposure

How the coast faces the swell — a sheltered cove keeps the water clean; an exposed, head-on point takes a penalty.

Safety gates

• Thunderstorm forecast — an instant red, no exceptions.
• An official warning (MeteoAlarm / IPMA) — yellow, or red for the higher ranks.
• Missing input data — a would-be green is capped to yellow rather than overstated.
• Strong disagreement between forecast models — a green day is pulled back to yellow.
• Night hours — where night spearfishing is banned by law the window is forced red; where it is legal (Australia outside NSW, New Zealand, South Africa) it is capped at yellow, never green.

It all folds into a single 0–10 score and one verdict: go or stay.

A forecast, not a guarantee — the sea has the last word.