Tidal Stream Compensation - Raymarine ST3000 Owner's Handbook Manual

Chapter 2: Using the Wheel Pilot 21

Tidal stream compensation

Under most operating conditions, Track mode will hold the selected
track to within ±0.05 nm (300 ft) or better.
The autopilot takes account of the boat's speed when computing
course changes to ensure optimum performance over a wide range of
boat speeds. If speed data is available, the autopilot will use the
measured boat speed. Otherwise it will use the default cruise speed
entered in Calibration Level 5 (see page 64).
Waypoint 2
Boat's speed over ground
Waypoint 1
D3261-2