The speed at which the GPS unit and the person operating it are moving with respect to the earth's surface.
The speed of the vessel relative to the bottom, as opposed to the vessel's speed through the water. The speed over ground includes the negative or positive effects of the currents in the water.
Digital reading that indicates your current ground speed. (Selectable in miles-per-hour, knots, or kilometers-per-hour)
(SOG) The actual speed the GPS unit is moving over the ground. This may differ from airspeed or nautical speed due to such things as sea conditions or head winds. For example a plane that is going 120 knots into a 10 knot head wind may have a SOG of 110 knots.
The actual speed the GPS unit is moving over the ground. This may differ from airspeed or nautical speed due to such things as head winds or sea conditions. For example, a plane that is going 120 knots into a 10-knot head wind will have a SOG of 110 knots. Also known as Speed Above Ground (SAG).
The actual speed the GPS is travelling regardless of direction.
