Editing Sea state (section)

{{Short description|General condition of the free surface on a large body of water}}
{{Redirect|State of the sea|the Venetian Empire|Stato da Màr}}
[[File:Wea00810.jpg|thumb|[[NOAA]] ship ''[[NOAAS Delaware II (R 445)|Delaware II]]'' in foul weather on [[Georges Bank]].]]
[[File:Figure 5- Wave Height of Different Sea States Compared to the National Security Cutter and a Cutter Boat (24718483131).jpg|thumb|Sea State 5 and 8 range]]
In [[oceanography]], '''sea state''' is the general condition of the [[free surface]] on a large body of water—with respect to [[wind wave]]s and [[Swell (ocean)|swell]]—at a certain location and moment. A sea state is characterized by [[statistic]]s, including the [[significant wave height|wave height]], [[period (physics)|period]], and [[wave spectrum|spectrum]]. The sea state varies with time, as the wind and swell conditions change. The sea state can be assessed either by an experienced observer (like a trained mariner) or by using instruments like [[weather buoy]]s, [[wave radar]] or [[remote sensing]] [[satellite]]s.<ref name=":0">{{Cite book |last=Holthuijsen |first=Leo H. |title=Waves in oceanic and coastal waters |date=2007 |publisher=Cambridge University Press |isbn=978-0-511-27021-5 |location=Cambridge}}</ref>

The short-term statistics describing the sea state are determined for a time interval in which the sea state is considered to be constant. This duration has to be much longer than the individual wave period, but shorter than the period in which the wind and swell conditions can be expected to vary significantly. Typically, the sea state is assumed to be constant for 15-30 minutes.<ref name=":0" />

The large number of variables involved in creating and describing the sea state cannot be quickly and easily summarized, so simpler scales are used to give an approximate but concise description of conditions for reporting in a ship's log or similar record.