Used to describe the combination or interaction of wind waves and swell in which the separate components are not distinguished. This includes the case when swell is negligible or is not considered in describing sea state. Specifically, seas = √(S2+W2) where S is the height of the swell and W is the height of the wind wave. When used, seas should be considered as being the same as the significant wave height.

This term is used to describe combined wind waves and swells (see swells).

Combined wind-waves and swell. Mariners often use the term to describe wind- waves only. Forecasters will normally use the term "combined sea" or "combined waves" to avoid this ambiguity.

Combination of swell and wind waves.

Waves generated by the action of wind blowing at the time of observation or in the recent past. Seas become swell at some point.