[CA] Procedure to align Evolution ACU-150 p70r Auto-Pilot to GPS

[karlista]

I need some help with subject. How do you align the auto-pilot to the GPS so the COG and heading vector lines on the Axiom Pro RVX chart screen are aligned.

Thanks

[Chuck - Raymarine - Moderator]

Karlista,

Upon completing the installation, did you execute the Dockside Wizard and then take the vessel out for a cruise to permit the autopilot to determine the table of deviation sensed by EV-1 CCU? If so, was the maximum deviation detected less than 10 degrees? Please click here to view a FAQ addressing these items. If the maximum sensed deviation is greater then 10 degrees, then the EV-1 CCU will need to be relocated further away from objects producing magnetic fields. Please click here to view a FAQ addressing this subject. If the maximum sensed deviation is less than 10 degrees, then heading may be aligned to COG via the command sequence MENU->SET-UP->AUTOPILOT CALIBRATION->COMMISSIONING->ALIGN COMPASS GPS. It is important to note that the vessel must be underway and making way to when aligning heading to COG. It is also recommended that the vessel be steered directly into the current to counter the affect of current induced leeway which may cause COG to differ from heading.

[karlista]

Q1. Upon completing the installation, did you execute the Dockside Wizard and then take the vessel out for a cruise to permit the autopilot to determine the table of deviation sensed by EV-1 CCU?
A1. Yes.

Q1. If so, was the maximum deviation detected less than 10 degrees?
A2. Yes. Deviation was only 2 degrees.

Q3. If the maximum sensed deviation is less than 10 degrees, then heading may be aligned to COG via the command sequence MENU->SET-UP->AUTOPILOT CALIBRATION->COMMISSIONING->ALIGN COMPASS GPS.
A3. Got it.

Q4. It is important to note that the vessel must be underway and making way to when aligning heading to COG. It is also recommended that the vessel be steered directly into the current to counter the affect of current induced leeway which may cause COG to differ from heading.
A4. I accomplished all of the above.

Q4. I performed all of the steps above when the auto-pilot was commissioned in Chesapeake, VA. The COG and Heading vector lines were aligned within one degree. When I moved the boat to Morehead City, NC, something changed and the COG and Heading vector lines of off by about 10 degrees.

[Chuck - Raymarine - Moderator]

Karlista,

Q1. I performed all of the steps above when the auto-pilot was commissioned in Chesapeake, VA. The COG and Heading vector lines were aligned within one degree. When I moved the boat to Morehead City, NC, something changed and the COG and Heading vector lines of off by about 10 degrees.
A4. Leeway can cause the heading and COG vectors to differ from on another. Should the problem persist when steering directly into the current, then it would be recommended that the Align Compass GPS feature be used again. Afterwards, you should still expect COG and Heading vectors to deviate from one another when the vessel is being subjected to leeway (wind and/or current). Leeway effects will also increase as the leeway magnitude to vessel speed ratio increases.

[karlista]

Thanks Chuck for the information. All good stuff.....

[Chuck - Raymarine - Moderator]

You're welcome.