The wave growth characteristics during the onset of summer monsoon in a swell dominated open ocean at a location off the west coast of India at 14m water depth are studied. 67% of the measured waves are due to the swells arriving from south and south-west and the balance was due to the seas from south-west to north-west. Wave age of the measured data indicates that the measured waves are young sea with presence of swells. Even when the wind speed reduced to less than 3 m/s, significant wave height more than 2m is present due to the swells in the Arabian Sea. The maximum wave height increased from 2 to 8m within 60 h. The mean wave directions at the high frequencies align with the westerly wind direction and gradually shift to south-westerly swell direction at low frequencies during the wave growth. The strong westerly winds present between longitude 72 degrees and 72.5 degrees at latitude 12.5 degrees has created the high waves (Hm0 upto 5.65 m) during the measurement period