What does the term 'SOG' refer to in a maritime context?

In a maritime context, 'SOG' refers to Speed Over Ground. This term is essential for navigational purposes as it indicates the actual speed of a vessel relative to the seabed. It is measured by taking into account the effects of current, wind, and other environmental factors that may influence a ship's movement. Unlike speed through water, which represents how fast the vessel is moving through the water itself, Speed Over Ground provides a more accurate representation of a vessel's travel speed over a specific distance on land, accounting for any external influences.

Understanding SOG is crucial for safe navigation, route planning, and maintaining efficient operation schedules. Mariners rely on knowing their SOG when determining their estimated time of arrival (ETA) at a waypoint, making it a vital metric in maritime operations.