3. Overview of Autopilot Operation

The rudder control and deadband control must be set properly for the CPT to hold the boat on a heading. Tack angles are approximate and will vary from boat to boat based on the magnetic environment and deadband setting, you will have to see which angle works best for your boat.

3.1. Turning the Autopilot On and Off

Turn the autopilot ON by turning the Rudder control clockwise from the OFF position past 1 to the desired setting (if unsure, set to 5). Turn the autopilot off by turning the Rudder control counterclockwise to the OFF position. Do not use a circuit-breaker or external switch to power the unit ON or OFF: when starting the autopilot, first turn the circuit breaker or switch ON and then turn the Rudder control ON (past 1).

Warning

Be sure to remember to turn the CPT Rudder control to OFF after getting into your berth or anchorage. It is easy to forget to turn the autopilot off during the activity of anchoring or berthing your vessel, dropping sails and putting the boat away after sailing. The CPT is very quiet, and will continue to operate after the clutch is disengaged.

If left in STANDBY mode the CPT will continue to draw current.
If left toggled to HOLD HEADING the CPT motor will continue running in an attempt to correct the boat’s heading and you may not hear or observe it. The motor is quiet and will continue operating for weeks or months until you return to your boat.

Always remember to turn the Rudder control to OFF before leaving your vessel in its berth or anchorage.

3.2. Setting Rudder and Deadband controls

The Rudder control should be set high enough so that when the boat falls off it is brought back to heading with just one or two “pulses” or wheel corrections. If the pilot makes repeated wheel corrections in one direction the Rudder control is set too low; the setting needs to be raised. If the pilot oversteers, lower the setting a bit. High Rudder settings provide larger rudder corrections, low Rudder settings provide smaller rudder corrections. The boat must be balanced and respond to the rudder in a consistent manner: the Rudder control sets the autopilot for one consistent response.

Start with the Deadband control (dead range) set to minimum, especially when first using the pilot. If the pilot is making port and starboard corrections too frequently, or reacting to swell, gradually raise the Deadband setting so that corrections are made when needed but are not constant. Low Deadband settings provides more sensitivity to heading changes, high Deadband settings provide less sensitivity when in swells and seas. A Deadband of 5 allows the boat to range approximately ±10° to port or starboard.

The CPT’s performance can be improved by careful tuning but continously adjusting the controls is not necessary. Once you find the Rudder and Deadband settings that work best for your boat, you’ll use the same settings most of the time.

3.3. A Note About Magnetic Headings

The CPT keeps a vessel pointing to a magnetic heading; this is not the same as a GPS course. In keeping to a compass heading, your vessel will point the same direction but still be subject to drift from wind and currents. This drift will be apparent when observing your GPS over time, and periodic heading adjustments will easily keep the vessel on your waypoint course.