Surface wind-waves properties during Indian summer monsoon is investigated based on measured data at 9-15 m water depth at 4 sites in nearshore waters of the eastern Arabian Sea. Significant wave height varied from 0.7 to 5.5 m with average ratio of crest height of wave to height of the same wave as 0.58 to 0.67. Extreme crest height is 1.23 to 1.35 times significant wave height. Measured waves were predominantly swell. Numerical wave model could estimate the wave height well during wave growth.

This study examines variation in wave power off the central west coast of India at water depths 30, 9 and 5 m based on buoy measured data. The study shows a significant reduction (~ 10–27 %) in wave power at 9 m depth compared to 30 m and the power at 5 m depth is 20–23 % less than that at 9 m. At 9 m water depth, the mean annual wave power is 6 kW m⁻¹ and interannual variations up to 19.3 % are observed during 2009–2014; 75 % of the total annual wave energy is from this narrow directional sector.

Using measured, modeled and reanalysis wave data and reanalysis wind data, we show that the Indian Ocean Dipole (IOD) plays a role in the variability of wave climate of the eastern Arabian Sea (AS). The change in wind field over the AS due to IOD influences the generation or dissipation of wave field and hence causes the decrease in northwest short period waves during positive IOD and increase during negative IOD.