Raymarine EV-100 Wheel Autopilot (06/2018)

Here are some notes on installing the Raymarine EV-100 wheel autopilot on a Catalina 270.

I searched for a page like this one and came up empty when I was researching my installation. If you are considering this installation, maybe these notes will help.

I had initially found lots of confusing information on whether this Raymarine autopilot can be installed on a standard NMEA 2000 network or not (as opposed to the Raymarine "Seatalk" network). The product info on the Raymarine website is particularly obscure about this and various forums hinted that yes it can but there was conflicting information.

The short answer is: YES. If you have a NMEA2000 network and are considering this autopilot, yes it works.

The longer answer is that it takes some tedious cable gymnastics, but the work is straighforward and it all works. I wrote a separate page on that here, check out the details: Networking the boat.


There are many pieces to the autopilot:
  1. EV-100 sensor core: this is the heading/compass sensor.
  2. ACU-100: This is the control unit.
  3. Rudder position sensor. This is not included in the base package but is highly recommended.
  4. Wheel drive: The disc and motor that hook up to the wheel.
  5. p70: The display and user interface.
I find that the documentation provided adds a lot more confusion than it should. The wheel drive manual is written to cover an earlier generation of this product and a lot of it does not apply, just confuse.


This is the easiest one. It can be installed anywhere on the boat but it needs to be on the centerline (they say) and facing the bow.

I installed it under the V berth as the Catalina 270 has empty space there and I had earlier installed a bulkhead which made for a convenient mounting spot.

The EV-1000 only has one connection. It plugs straight in to the NMEA2000 network (after modifying the cable).


This is the CPU of the system and has many connections. It can be installed anywhere but it needs to be vertical (on a bulkhead), I'm not sure why.

It has the following connections:
  1. Dedicated power (up to 7A load).
  2. Drive motor (which gets its power through the ACU-100).
  3. NMEA2000 network (so it can talk to the EV-100 and the p70 display).
  4. Rudder position sensor.
Even though it can be installed anywhere on the boat, the above wiring requirements will largely dictate where it can go.

On the Catalina 270 I installed it on the bulkhead behind the aft cabin. This puts it near the rudder post (immediately behind) and steering pedestal (right above).

Rudder position

This took by far the most effort. It needs to be parallel to the rudder post rotation so every boat will need some kind of custom mounting solution.

Here's what I came up with for the C270:

Wheel drive and motor

When I first opened the box and started to eyeball the installation I got worried this may not fit the C270. The factory engine gauge cluster takes up a lot of space and it wasn't clear whether there was enough left for the wheel pilot.

In the end, it did fit! But it was extremely close...

The main problem is this rod which keeps the wheel drive in place. As seen on the photo below (click to enlarge) the rod is tight against the gauge cluster and also at the highest possible point in its slot on the wheel drive. If the factory gauge cluster had been even 2mm higher on the steering pedestal, it would not have worked. Whew!

Another problem is that the clutch lever hits the gauge cluster when lowered (engaged). I had to cut off more than half of the lever arm so that it can be fully engaged. It works fine as there is very little force needed on it, so the loss of leverage is not an issue. Just doesn't look quite as nice but most people probably won't notice.

I ran the wire from the motor (the black plug on the photo above) up to the navpod and then down the steering guard tube into the aft cabin. From there it routes to the ACU-100 control box.

p70 Display

Mounted up in the navpod with the other displays. Only connection is to the NMEA2000 network (after modifying the cable).


After a year of use (including one week-long cruise) I can say I'm very happy with this autopilot. Would definitely buy it again.

I use it heavily given that most of my sailing is single-handed. I only hand steer in and out of the harbor, most of the time out in the ocean the autopilot is always steering. Nearly all the time I use it wind mode, where it keeps the wind angle consistent.

One annoyance is that if the wind shifts, it starts beeping a wind shift alert for a long time (unless I press a button to stop it). While this seems like a nice feature, I'd expect it to only alert for significant wind shifts. Unfortunately it will beep away for even a 3 to 5 degree wind shift which is very silly. I wish the minimum wind shift angle was configurable but it is not. So in slightly shifty winds, it ends up beeping all the time and I have to constantly silence it. On the plus side, it continues steering just fine even while beeping, so if I can't get to it I can just ignore the beeping.

I've sailed it in winds from 5 knots to 30 knots without issues. As long as the sails are balanced (and reefed above about 20 kts) it steers fine all day.

In short-period swells above ~5ft or so it can't steer that well. When hand steering, I see the waves coming and can anticipate them but the autopilot can only react after the fact, which means it ends up swinging the course a lot. Can't really call it a fault because it has no way to see the waves but something to be aware of. When the swells are above 5ft and winds are above 20kts I tend to always hand-steer. The autopilot can still steer in these conditions if needed, so if I want to go down below for a moment it works ok.


The major bug in this autopilot is the auto-tack feature. It basically doesn't work at all, which is very disappointing.

Pressing 1 and 10 together (either + or -, depending on tack) is supposed to auto-tack the boat so I can concentrate on releasing the jib and sheeting it in on the other side. It is a wonderful feature for a single-handler. Unfortunately, it doesn't really work!

What happens is that the autopilot heads up across the wind but after the bow is only a few degrees to the new tack, the autopilot suddenly centers the wheel!!! So it doesn't turn enough to complete the tack. The boat either ends up in irons or (most often) just swings back to the original tack (meanwhile, I've sheeted in the jib on the other side already, so now we're hove to).

Every now and then it keeps turning enough to complete the tack but 80%+ of the time it fails miserably. Very frustrating. Seems like this should be a simple feature to get correct but Raymarine completed messed it up. It doesn't work.

Still.. for the price this autopilot works well and I recommend it. Just be aware the auto-tack is broken.

Back to my Catalina 270 page.