Spectra of Hawaiian region NDBC buoy data:

Figures below courtesy of data from the National Data Buoy Center
links to NODC buoy pages: 51101,  51201,  51003,  51003

All plots are made by matplotlib , a rapidly developing
open source alternative to matlab, written in python.

This experimental page shows non-directional spectra with the same scale.
(improvements are anticipated)
Another page exists with independently-scaled spectra

51101
buoy 51101 spectra
51201
buoy 51201 spectra
51003
buoy 51003 spectra
locations
buoy location map