Installation manual

Simrad SP70
108
850-164186 / Rev.D
Dead Reckoning
Dead Reckoning is accessed from the Setup menu.
Dead Reckoning is used to improve the position of the
historical track line from the vessel, relative to the actual
position of the drifting fishing gear.
When OF F, the vessel movement and track line will be
calculated from the GPS data, which then will be relative to the
bottom.
When ON, the gyro and speed log are used to positioning the
vessel relative to the water.
In order to get correct dead reckoning, a doppler speed log must
be connected to the sonar.