I was about 15nm from Mallorca when my autopilot finally gave up the ghost. It was a Cetrek 770 unit which makes it at least half the age of my 1977 Prout Snowgoose, maybe even more, but that didn’t stop me cursing it a little for the final two and half hours of the trip.
I’d actually been considering a unit for a while, but as they say, ‘if it ain’t broke, don’t fix it.’ Principally, I wanted something that would hook up to the Simrad NSS8 chartplotter and automatically steer a plotted course. Naturally that steered me (pun intended) towards a Simrad/Navico/B&G unit. In particular the NAC-3 VRF Core Pack.
Unfortunately, that was nowhere to be found in the usual online chandleries. An Internet search didn’t turn up much either. And that’s another thing. At the time, I was also considering the Raymarine Evolution system. Not only was this widely available (even at next day delivery from UK to Spain), but there was tons of information about it online. Forum posts, blogs (see The Marine Installer’s Rant for some good information on this system), and even Raymarine’s own technical section. That was enough to close the deal. Well, that and the fact that sailing single-handed can be difficult enough as it is, let alone without an autopilot, I wanted something ASAP.
The unit arrived DHL Express, and I set to work installing it immediately. The process is pretty straightforward, but the rolley anchorage in Calanova made it anything but. First impressions were good. The ACU-200 which drives the pump was a nice solid unit, a lot beefier than the Cetrek. The EV1 sensor looked simple and easy to mount, and the P70s control head seemed nice. The pack also came with a rudder position sensor, and SeatalkNG backbone and spur cables.
Here’s how it compares to the much older Cetrek unit.
As you can see the actuator unit is noticeably larger and beefier despite the plastic cover on the front. The compass, is actually the black circle in the white housing. The Cetrek unit here was an all metal housing. Very heavy and robust. In contrast the Raymarine EV-1 is light and not necessarily flimsy, but not as strong as the old unit (but I’ll get to that later).
The P70s control head is a more conventional square unit as oppose to the Cetrek remote control. It has a full colour display and menu system to setup the pilot, with the main control buttons easily accessible. Oddly, there is no ‘tack’ button though.
Installing the ACU-200 acutator unit
I originally wanted to mount this in the cupboard below the helms station, but I found that the unit was too large and bulky to compete for space with the rats nest of wires in there.
I’d say sorting those out and labelling them is a job to add to the list, but we all know it will never get done, otherwise I imagine the previous owner would have already done it.
Instead, I settled on the same location as the old unit, which was under a shelf in the port-side hull. All the necessary wires were already in place. All I had to do was to drill new mounting holes, and make a hole for the SeaTalkNG cable.
One thing I found confusing is the was the ‘ground’. As well as positive and negative power cables, the unit also has a separate connector for ground. Now on my boat, ground just goes back to the battery bank, so I’m fairly sure I could just connect it back to the negative wire that is already going into the unit. Perhaps someone reading this can comment. For the moment I have left it as is since according to Raymarine it’s not 100% necessary.
Installing the EV-1 compass
Installing the compass/heading unit was probably the most difficult part of the whole process. Not because it’s actually difficult but because I couldn’t fathom where to put it.
The instructions call for it to be placed at least 1 metre away from power cables, away from the VHF radio and it’s associated cables, away from ferrous metals, and even away from the ACU-200 unit. On a 10.5m boat, that just about leaves it in the sea. Difficulty in placement is compounded by the fact that the cables are super short too, and you’re not supposed to extend SeaTalkNG spur or backbone cables.
In the end, this went in the exact same place as the old compass, which is 40cm opposite the actuator unit. Not ideal, but it fits nicely there, and since the old system didn’t have a problem, why should this newer more advanced system?
On the subject of the compass. I found that mine came already sealed/closed in the plastic housing, however it was the wrong orientation. I opened the plastic housing according to the instructions, i.e. by pushing in the plastic tabs. I then re-orientated the compass and closed the housing. I soon found, due to placement problems, I needed to open the housing a second time and re-orientate the compass yet again.
It seems that the plastic is cheap, nasty, and brittle. It cannot withstand being opened multiple times. The small tabs that secure the unit together fatigue and break. At over £1,700 for the (total) system, I expected better. Especially considering that the old compass was housed in a very solid metal case.
The damage to the tabs means that when put back together, the case doesn’t close tightly. Since it is inside, in a dry stable area it’s not a huge problem, but still, it’s something that should never happen. I mentioned this when I contacted Raymarine support, but they glossed over the issue. I might still put in a warranty claim, but it seems excessive when I could get by with double-sided tape.
The Raymarine P70s and hooking it all up
The P70s control unit is the last part of the puzzle. I think that if I had a Raymarine MFD I could probably have done away with this, but since I have the Simrad NSS8, the controller is needed to setup and engage the autopilot.
Perhaps this article should read ‘How to half set up an autopilot’ as I still haven’t properly secured the P70 control unit. The controller didn’t come with a template, which I found I strange, and I haven’t yet acquired an 88m hole saw (I don’t think I ever will), so need to get hold of a small reciprocating saw to finish the job properly.
I’ll probably end up moving my wind instruments, depth log, and the very badly positioned analog compass (which needs re-calibrating) to make room.
First things first. I knew the control unit was going to positioned at the helm station – duh! That meant I needed a long SeaTalkNG backbone cable and T-piece to reach from the included 5-port hub, a couple of meters away to the helms station.
It should have been simple enough to install. I suppose in a way it was, just laborious. To keep the cable out of sight, I first had to run it under the floor (but not in the bilge) in the port-side hull. Then through the rear bulkhead into the cupboard under the helms station. This meant first removing the ceiling tiles, which meant disconnecting the lights, then removing my plywood wall panels. Basically, just dismantling the saloon. It reminded me of an old BMW motorcycle I had where the procedure to top-up the coolant starts by removing four bolts from the left side indicator – WTF!
With those items removed it was easy as pie to drill the correct sized hole and feed the cable through and hook up the control unit.
Setting up the system
Once powered up the system is super simple to set-up. All that is required is to run the dockside wizard and follow the onscreen prompts and menus.
Here you’re asked to choose a hull type, catamaran in my case, choose the drive method i.e. tiller, hydraulic etc.. then enter some details about your vessel. Firstly the max-rudder angle, on Jade this a measly 20 degrees, and then the hard time over. That is the time it takes the hydraulic pump to turn the rudder from lock to lock. This is tested by turning the rudder to full lock, port or starboard, then connecting a 12v power source to the pump and timing it. In my case the rudders go from lock to lock in about 11.5 seconds. I’d recommend centring the rudders first and just testing, to make sure you’ve hooked up the power the right way, so not to strain the system.
Note – if you use the included rudder position sensor, then you don’t need to worry about the hard over time. I couldn’t fit the rudder position sensor in the space I had where my old one sits. I did try connecting the old one up to the Raymarine unit, but it is a good 10 degrees out even when maxing out the rudder offset compensation.
It’s worth experimenting with these profiles, as they may not fit your vessel. For instance. Jade is a catamaran, but doesn’t have quick light flickable steering like newer catamarans, so Sail (slow turn) could be more appropriate.
Once you’ve entered these details, the system will then carry out some tests. Firstly it will try to turn the rudder to port. If the rudder moves to starboard instead, you simply select “no” (see the screen below). It will then ask if the rudder turned to starboard, to which you’d respond “yes” and the unit then reverses the polarity of the pump.
That’s essentially it. The next step was to take the boat out and drive around in a circle at a speed greater than 3 knots. This allows the compass to automatically calibrate itself. In my case it took about half a turn.
Once complete, you can check the magnetic deviation of the compass in the menu under ‘Diagnostics’ and ‘About pilot’. In my deviation was 10 degree, but later dropped to 9 degrees with further use.
That’s another thing. Unless you specifically lock the calibration, the unit will continue to learn as you use it. Once you feel it’s working how you’d like, you can then lock in those settings.
Connecting the Raymarine Autopilot to the Simrad NSS8 MFD
As I mentioned at the start, I was already considering a new autopilot so that I could integrate it with my existing multifunction display. I was unable to go for a Simrad autopilot due to availability and shipping. So Raymarine it was.
Since the Raymarine system runs on the SeaTalk NG network, and the chartplotter is just a standalone unit at the moment, really what I was doing was connecting the chartplotter to the autopilot rather than the other way around.
In this case what I needed was a SeaTalk to DeviceNet adaptor.
Unfortunately the one pictured above wasn’t what I needed. It turns out Simrad do everything backwards, so rather than a male DeviceNet adapter, I needed a female one. €30 and three days later it finally arrived, then it was a simple as just plugging it in.
Once connected the NSS8 automatically chose to use the EV-1 as its heading sensor, and noted the autopilot on the network. Likewise, the autopilot picked up the GPS signal from the MFD.
Even with 400w of solar, and 675ah of battery power, I still I like to keep tabs on my power usage. I have been running the autopilot in a mixture of Performance, and Cruising modes. In Performance mode it spikes roughly 10 amps each time it engages the pump. That’s not a continuous 10 amps, but short bursts lasting a few tenths of a second.
In cruising mode the peaks seems to last longer, but are less frequent, and draws slightly less amps. I haven’t really experimented with leisure mode, as I think it might be a little too lethargic for my tastes.
Routing and integration
Once I set a route on the chartplotter, I can select ‘track’ on the autopilot controller, and the pilot will then follow that route up until it reaches a way point. Then it will ask if you want to turn to the next waypoint. It’s not the complete integration I ultimately wanted, I’d need a Simrad/B&G/Lowance system to achieve that, but it works well, I generally only have a few way points per route anyway, so it’s not really and issue.
Overall I’m pleased with the system, but it does leave some questions as to where to go from here? At some point I need to update the charplotter. I like the B&G sail-steer software, and hardware options in the Zeus3 or Vulcan 9, they will be plug and play with my existing 3G radar, but would it make sense to now change to a Raymarine plotter and but a new radar.
Something to think about over the coming winter perhaps.