Custom Date Range

Please be aware that it will only show the data from the start of our monitoring programme for this site. When selecting large date ranges please be patient as the result may take time to return all the data required. If requesting more than 6 months' worth of data, please note that the chart will reduce down the intervals of data displayed.

Date/TimeLatest Reading

The significant wave height graph features coloured bands that estimate sea conditions for a given wave height at the buoy.

This is based on the Douglas Sea Scale's "wind sea" definition, used by the World Meteorological Organisation (WMO) and NZ MetService.

For simplicity, wave heights under 1.25 m are labelled as "Slight" instead of being split into "Calm" and "Smooth," as per the original scale.

Douglas Sea Scale

The values of the various categories within the Douglas Sea Scale are shown in the table.

Sea State Code Wave Height (m) Characteristics
0 0 Calm (glassy)
1 0 to 0.1 Calm (rippled)
2 0.1 to 0.5 Smooth (wavelets)
3 0.5 to 1.25 Slight
4 1.25 to 2.5 Moderate
5 2.5 to 4 Rough
6 4 to 6 Very rough
7 6 to 9 High
8 9 to 14 Very high
9 Over 14 Phenomenal
Significant wave height is the average of the highest third (33%) of waves, as larger waves have more impact and can do more work, such as driving coastal erosion.

The Significant Wave Height data on the website is RAW. It has come straight from the Council's automatic telemetry system and partner agencies, so has not been through a quality control process. It should therefore be treated as preliminary data and may be subject to change. For more information or quality assured data please contact hydrologydata@wcrc.govt.nz with details of your request.