Sea state

Sea state refers to the general condition of the sea surface at a particular location and time. It is typically described by parameters such as wave height, wave period, wave direction, and the presence of swell. Sea state is influenced by factors like wind speed and duration, fetch (the distance over which the wind blows), and bathymetry (the depth and shape of the seafloor).

Sea state is an important consideration for a wide range of maritime activities, including shipping, naval operations, offshore oil and gas exploration, and coastal engineering. High sea states can pose significant risks to vessels and structures, leading to damage, delays, and even loss of life. Accurate forecasting of sea state is crucial for planning and conducting these activities safely and efficiently.

The World Meteorological Organization (WMO) Sea State Code is a commonly used system for visually estimating sea state based on observed wave characteristics. This code assigns numerical values to different sea states, ranging from 0 (calm, glassy) to 9 (phenomenal). These codes are often used in weather reports and forecasts.

Beyond visual observations, sea state can also be measured using instruments such as wave buoys, radar altimeters on satellites, and acoustic Doppler current profilers (ADCPs). These instruments provide more precise and detailed information about wave characteristics than visual estimates.

The term "sea" itself refers to the waves generated by local winds, while "swell" refers to waves that have traveled from distant storms. The overall sea state is a combination of both sea and swell. Differentiating between sea and swell is important for understanding the dominant wave processes at a given location.