The PIERON-MOSKOWITZ (PM) ocean wave spectrum, derived from analyses of many ocean wave records, contains two constants α and β for fully arisen sea (FAS) conditions. This frequency spectrum can be converted to a period base, termed an energy distribution curve (EDC) that contains the same contants. The EDC is almost triangular in shape, with the period Tmaxat the apex increasing with the steady wind velocity. A unique relationship result between the ignificant wave height H⅓and Tmax.