MHL, Manly Hydraulics Labs has seven continuously recording buoys off the NSW coast that provide deepwater wave data.
Sydney buoy (no relation to Danny Boy) is moored 10 kilometres due east of Dee Why point in water 100 metres deep.
Remember that these are swells on the ocean not the faces of breaking waves on the beach. This buoy also measures wave direction (others don't).
Its current readings:
Hmax - is the largest individual wave recorded in the 34 minute sampling period.
The biggest swell height. Groundswells (longer period swells, see Tp1) can have "clean-up sets", waves that appear to come out of nowhere.
Direction in degrees where 0 degrees is north (N) and so is 360 degrees. Typically the reading here will be between 90 and 180, or E & S.
Generally, the direction is the direction of Tp1, see below.
Tsig - Significant period = average period of the waves used to define Hsig.
Measures the time between one wave and the next. Close your eyes and imagine a good surf, then imagine a bad surf of the same size. The difference is mostly how far apart the waves are (and the surface chop).
Tp1 - Period of the peak of the energy. The highest reading. There usually is more than one swell being recorded, this reading will give a hint about the best swell.
Still having trouble with degrees & direction?
Think of a clock face with 12 o'clock being N; 3 o'clock is east (E) or 90 degrees; 6 o'clock is south (S) or 180 degrees.
IMPORTANT: This information has been recovered directly from automatic recording equipment and has not been quality controlled by MHL.
This data has been collected under the NSW Coastal Data Network Program managed by Office of Environment and Heritage (OEH).
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