In most cases ocean waves are caused by winds blowing over the sea. Waves transmit a lot of energy across the ocean, the energy value can be found by using wave power formula for the wave energy flux, Watt per meter of crest length:
P = ρ*g2*T*H2/(64*π), [W/m] [1]
where
H - the vertical distance between crest and trough of the wave, meters;
T - the period of wave, seconds;
g - the acceleration of gravity, m/s2;
ρ - the mass density of sea water, kg/m3;
π - 3.14159
The wave energy per square meter can be calculated using this formula:
E = ρ*g*H2/16, [J/m2] [2]
Both formulas are correct for depth more than half the wavelength.
Source: A review of wave-energy extraction by Johannes Falnes, Marine Structures 20 (2007) 185 – 201