A description of the condition of the sea surface with respect to wave and swell characteristics, categorised using the Douglas Sea Scale from 0 (calm, glassy) to 9 (phenomenal, waves over 14 metres). Sea state affects vessel safety, speed, cargo securing, and crew comfort.
Category: Weather & Sea Conditions
On The Maritime
The desks that work with Weather & Sea Conditions terms.
Related terms
More in Weather & Sea Conditions
HurricaneA mature tropical cyclone that develops in the North Atlantic or eastern North Pacific Ocean, characterised by sustained wind speeds of 64 knots or greater.MonsoonA seasonal prevailing wind in the Indian Ocean and southern Asia that brings heavy rainfall during summer months.Neap TideThe tide with the smallest range between high and low water, occurring approximately every two weeks when the sun and moon are at right angles relative to the earth during first and third quarter moon phases.Spring TideThe tide with the greatest range between high and low water, occurring approximately every two weeks when the sun, moon, and earth are aligned during new and full moon phases.Storm SurgeAn abnormal rise in sea level generated by a storm's winds and low atmospheric pressure, over and above the predicted astronomical tide.Tidal RangeThe vertical difference between the highest high tide and the lowest low tide at a particular location.
Back to DictionaryEntry updated May 2026