Garmin GHP12 vs Reactor40 autopilot CCU upgrade

[HUN-12214]

Hi

Has anybody info about the differences of the Garmin GHP12 and the Garmin Reactor 40 CCU? Is it worth upgrading?

I have a light displacement, fast, 45 feeter sailboat. She surfs quite well. My garmin autopilot with class A (Jefa) linear drive is usually OK, but I am not really impressed with the downwind performance in big waves. I have a full Garmin system with Nexus NX2 instruments. I am not considering to change to racing level nke or b&g autopilots because of cost and potential compatibility issues. The CCU upgrade to the new Reactor 40 is within my reach, but I am not sure if it really has any real benefit in practice.

I am new here, this is my first post :-) I will really appreciate any answer. thanks.

[hvandervliet]

Hi I had the GHP12 with GHC10 and old ccu and LD100 on my previous Beneteau first 31.7 and was very satisfied. On my current boat, Jeanneau Sun Fast 40, I have the same setup but with the GHC20 and new reactor ccu. With the SunFast I’m not very satisfied downwind in big waves. It seems to not correct fast enough when it overshoots to leeward or windward on a wave. Sometimes I get the feeling that it’s not correcting the overshoot at all for a long time. I tried various settings for response and as well used both TWA and AWA settings. I have the impression it’s not a problem of torque power but more a software problem related to boat characteristics. Did you achieve any improvements in the mean time?

[HUN-12214]

Hi, thanks for your comment. In the meantime, we've completed an Atlantic crossing so we had plenty of time to play with the ccu in downwind sailing conditions. We could figure out the right settings for our boat and for the given conditions. Finally she sailed under the autopilot like an Imoca60 . Unfortunately the joy lasted only a few hours. The linear drive gave up... There is a "weak link" in the Garmin (=Jefa) linear drive (a metal/plastic gear). Our boat is usually very well balanced with minimal rudder force but sometimes enormous forces are generated in downwind sailing when a big wave hits us from the side.
So my final conclusion was: to keep the the GHP12 and to replace the drive unit. I have already purchased a big Jefa drive but I haven't had a chance to try it yet because of the covid situation (The boat is in Caribbean, I am here in Europe...) ... sad...

[hvandervliet]

Sad to hear. We have cruised in the Caribbean in 2015/2016. We crossed by plane and the boat travelled on a freighter by Sevenstar. Wonderful cruising and good memories? I hope you will be able to continue soon.

Thanks fo the good advice on the Jefa LD100 weakness! I was planning to invest for a spare, maybe it’s better to invest in a heavier drive. I think the LD100 is very efficient in light/moderate weather. Maybe should combine this with a heavier drive as backup and for heavier conditions. Do you plan for the Class B (i think as well Jefa based) or a Hydraulic system?

Can you share more details on your settings which brought success? What kind of gain and counter rudder settings did you use? What response setting and economy percentage? What particular setting(s) did the trick in those conditions? Did you use wind hold (AWA?) or heading hold?

[HUN-12214]

Unfortunately I do not remember the numbers. Autocalibration first and then very little changes, step by step.
Agree, the Jefa linear drive is very good in moderate weather. I bought a Jefa DD2, a much bigger electro-mechanical drive . The garmin class b is a hydraulic one (made by Hy-Pro, I guess). I prefer electro-mechanical drive over hydraulic (less drag).