North of Pt St George, combined seas 20 feet or greater. South of Pt Arena, combined seas 15 feet or greater. Gale Warning - Wind of 34 knots to 47 knots sustained or frequent gusts. The speed at which a particular wave front or swell train advances. Seas - Waves generated by the action of wind blowing at the time of observation or in the recent past.
Seas become swell at some point.
It also approximates the value an experienced observer would report if visually estimating sea height. Small Craft Advisory - Wind of 21 knots to 33 knots sustained or frequent gusts. Small Craft Advisory for Hazardous Seas or for Swell - Combined seas of 10 feet or greater. Storm Warning - Wind of 48 knots or greater. Swell - Wind waves which have traveled beyond the wave generation region.