Raymarine ACU 400 AP

Paul Osterberg


I have installed the Raymarine ACU 400 Auto Pilot together with new Raymarine instruments, I use my old Autohelm AP electronics as back up. I kept the old drive units, so only the electronic part is new.

I did expect better performance from the new system even though I was rather happy with the old system.

The new system works OK going up wind can't say it is better than the old system.

The problem is down wind the new is inferior to the old system. I assume it is a trimming but it is rather awkward to adjust as one need waves and high wind but if you have that you can't have the AP in Auto but it must be in stand by to adjust settings that are rather fare down the menu, not very user friendly.

When going down wind the course is not very straight on the contrary one has to gard it very carefully and sometimes take over and do manual steering, which i have not needed to do with the old electronics, with the old we have sailed down wind with 40 knots apparent wind so true has been close to 48 knots and the course has been rather stable. even with rather large sea.

Now we have problem when wind approaching 20 knots and waves less than 2 meters. 

The setting we have is 

Hard over time 16,5s

Rudder damping 2

Display response 5 for speed and wind, do not now if that influence the AP performance , can't say I'm impressed of the manual who cover tree different AP .

can't say it's a big difference when using Performance, Cruising or Leisure settings for Response level 

Anyone having this system on an Super Maramu, what are your settings? How does it perform for you?

Any advice how to trim the system?

Paul on SY Kerpa AM#259

Join main@AmelYachtOwners.groups.io to automatically receive all group messages.