if a beach faces E. then the offshore wind direction is W.
Wind direction on Swellinfo is stated by the meteorological convention, stating where the wind is coming from. So, a West wind, comes from the West and blows towards the East. This allows for clean conditions as apposed to wind coming from the ocean towards the shore.
The further away from directly offshore, generally the choppier the surf is.
The lighter the winds, the glassier the conditions.