Speed Over Ground (SOG) is the speed of a boat relative to the Earth’s surface, taking into account external factors like wind, currents, and tides. It is usually measured by GPS or LORAN-C and takes into account the speed of the vessel in relation to a fixed point on the Earth’s surface. SOG takes into account the speed of the boat in relation to the water, abbreviated STW.
In sailing, Velocity Made Good (VMG) is a term used to indicate the speed of a sailboat towards or from the direction of the wind. This concept is useful for new boat owners, whether they bought a jet ski or a 40-foot cabin cruiser. SOG stands for Speed Over Ground, which refers to the speed at which the boat is moving without considering the wind direction.
Satellite receivers measure actual speed against the Earth itself, calculating what is called Speed over the Ground (SOG). If it is more than one second apart, SOG stands for Speed Over the Ground. The term “SOG” stands for Speed Over the Ground, while “STW” is the speed of the vessel relative to the water.
SOG is the true speed of progress of a vessel between two points with respect to the Earth’s surface. The vessel’s SOG may differ from its speed due to various factors, such as wind, currents, and tides.
Speed Through Water (STW) is the speed of the vessel relative to the water. It is possible for the STW to be zero while the SOG is 5 knots. SOG is the speed that you are moving at over the surface of the Earth, while SOW is the speed through the water. Water is a fluid and rarely stationary, so understanding these terms can help you navigate your boat safely and efficiently.
📹 Ship Speed Comparison – SOG and STW
Shipspeed #SOG #STW It is confusing for the seafarer on which ship speed to use – SOG or STW? Let’s do a ship speed …
📹 Speed over Ground (SOG) & Speed over water (SOW)/STW Explained
This is a video detailing the SOG and SOW with examples of numerical as well as from the ship’s GPS and Doppler Log.
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