The JONSWAP analytical expression for the fully developed wind‐generated ocean wave field was fitted to mean observed spectral forms derived from selected observations made at the Maui A gas production platform (39°33′S, 173°27′E) west of Cook Strait, central New Zealand. There was close overall similarity between the New Zealand and the North Atlantic spectral forms, but the mean peak enhancement factor for the New Zealand spectra (1.55) was lower than that derived in the JONSWAP experiment (3.3). This difference may be associated with the long distance, long‐duration fetch characteristics of the site, which is open to the Southern Ocean south of Australia.