Nav System Upgrades

Warning… geek-ish content.

Miss Miranda’s navigation system is put together from high quality components, mostly from Furuno, but I believe they are original to the boat, meaning that they are nearly 20 years old.  Furthermore, none of the systems have any built-in redundancy, so failure of one component could have some pretty serious consequences.  I would love to install a brand new, fully redundant system, but frankly, we could not justify the expense, which could easily exceed $100,000.  So, I’ve been thinking about how we might slowly upgrade and modernize the system while creating some redundancy.

The main components of the system are:

• Furuno GPS for position and course/speed
• PC-based chart plotter software, originally Nobeltec “VNS” which I have replaced with Rose Point Coastal Explorer and Nobeltec TimeZero Navigator.  More on that later
• Furuno 1932 Mk II open array radar.  This model has a standalone “green screen” display but works very well.  What it lacks is an optional module for ARPA (Automatic Radar Plotting Aid), which allows you to track a radar target (i.e. another vessel).  We had the same radar with this module on our other boat, and I really miss not having it.  I think it is one of those critical safety components.
• Furuno FCV585 fish finder.  This is a depth sounder with a color display to show bottom contours.  It also shows water temperature.
• Simrad AP20 autopilot.  The autopilot allows us to steer a course based on boat heading, but is also integrated into the chart plotter so that it can follow a route.  It also provides rudder control for the 3 additional steering stations on the boat, located on the port and starboard portugese bridge and the cockpit.  These are super handy for docking.
• Airmar PB200 weather station.  Provides weather information, notably wind speed and direction.
• Furuno RD30 display.  This is a multi function display for navigation and weather data, typically things like boat speed, position, wind speed and direction.
• ICOM VHF radios.  One of these radios has DSC (Digital Selective Calling) which allows us to transmit our location over VHF in the event of an emergency.
• Vesper XB8000 AIS receiver. This is a recent upgrade and is a very nice addition to the system. It broadcasts our position, and also receives position data for other AIS equipped vessels. Very handy for places where there is a lot of marine traffic. It also has a high quality GPS receiver and has wifi capability, so it can send data to mobile devices.

We decided that the critical systems for which we would want backups were GPS, Radar, Autopilot, and Chartplotter, probably in that order. We already had multiple GPS sources, and just needed a way to move the data around. Therefore, our goals for the upgrade were:

• Be able to deliver navigation and weather data to multiple devices, including a second navigation PC and over the wifi network to various iPads. Most of the navigation data on the boat is shared by a marine networking standard called NMEA 0183, which is essentially a point to point serial communication protocol (does anyone remember serial ports on early PCs?). The data are sent to the PC via 4 serial to USB converters, which makes it difficult to send to more than one PC. Furthermore, some of the navigation devices are “daisy chained” together, for example, the fish finder gets GPS data in and therefore sends out both depth and GPS data. This results in duplication of data streams… messy.
• Install an additional radar for backup and for the ARPA capabilities that I described above.
• Install a second autopilot system as a backup.

The key component for making all of this possible is the Rose Point NEMO gateway. Rose Point describes it better than I can:

The nemo gateway connects your onboard data systems to provide your PCs, tablets, and phones access to all of your marine electronics. It can also translate information between NMEA 2000 and NMEA 0183 so you can use a combination of older and newer devices rather than upgrading everything at once.

When I learned that the NEMO would be on sale at the Seattle boat show, I decided to take the plunge. I bought the NEMO, a Furuno DRS4D-NXT solid state radar (with a name like that, it must be good, right?) and a Furuno NavPilot 711c. I then enlisted electronics expert Steve Elston (http://www.elstonmarine.com/) to do the install with me and teach me a bit along the way.

Here is a diagram of what I hoped to have at the end of the project. We will replace the existing NMEA 0183 “network” with a small NMEA 2000 (the current standard) network as well Ethernet and wifi networks.

NEMO Installation

The first step was to identify all of the existing NMEA 0183 connections and wiring. Opening up the pilot dashboard panels was truly frightening – a mass of unlabeled cables running in all directions. It took a solid day for the two of us to clean up the wiring and trace all of the connections, giving the label maker a good workout as we labeled each end of the existing cables. Once that was done, installing the NEMO was quite straightforward. The cables that had USB connectors for the PC went instead into the NMEA 0183 inputs and we wired a couple of NMEA 0183 outputs to send signals to the devices that needed 0183 inputs (Autopilot, fish finder, radar, radio). We then created a small NEMA 2000 network to connect the Vesper AIS transponder to the NEMO, and we created an Ethernet network to connect the nav computers. Once everything was connected, we were able to use Rose Point Coastal Explorer and/or the NEMO web interface to configure the device.

We ran into a couple of interesting challenges along the way:

• For some reason, we were not getting the depth output from the Furuno fish finder. It had been working before the upgrade, and we spent a lot of time diagnosing the problem. It turned out that the NMEA output chip on the 20 year old device had died. We were able to send it back to Furuno to repair, and were also able to get the screen, which was beginning to delaminate, repaired at the same time. I think it is very impressive that Furuno actually repairs 20 year old equipment. They have earned my loyalty.
• When we got the fish finder back, we were getting depth on the network, but not to the Furuno 1932 radar. After another prolonged but of diagnosis, we discovered that the plus and minus wires had been crossed in a hidden splice far down the cable. It was one of those “what the @#$% were they thinking?” moments.
• Finally, when we were configuring the PC navigation systems to use the UDP data stream from the NEMO, TimeZero seemed to be getting the wrong heading data. The source, we knew, was supposed to be the fluxgate compass for the Simrad Autopilot, and we could see that Coastal Explorer was receiving and displaying the data correctly, but for some reason, TimeZero was not. It turned out that the fish finder was sending an inaccurate heading through water (VHW) sentence that TimeZero was using instead of the standard HDG sentence. There was no way to turn it off at the device, but I was able to filter it out of the UDP data stream using the NEMO console.

I am very happy with the NEMO. I can now run two (or more) navigation PCs on the network (but make sure that only one is trying to control the autopilot!) and all of the data from the NMEA 0183 devices is converted to NMEA 2000. That means that the Vesper can rebroadcast all of the nav data over wifi so I can use it with an iPad running iSailor.

Radar Installation

The next phase of the project was to install the Furuno radome. Before doing that, we had to remove the KVH trackvision system – the Furuno dome was going to replace the unused KVH dome up on the stack. The removal and replacement was uneventful for the most part, with the biggest challenge being getting access to the upper part of the stack to pull and secure the signal/power cable. The only way to get to it was to pull off a stainless steel vent grate that had been extremely well sealed into place. Nothing that a little bit of heat and a lot of salty language couldn’t fix. Once physically installed, all I needed to do was to configure the Ethernet network to live in the Furuno proprietary address range. I purchased the optional radar module for TimeZero and was up and running in no time. The only configuration needed was to tweak the alignment setting to account for the dome not pointing perfectly straight ahead. TimeZero allows the radar to be displayed standalone in a separate window, or as an overlay on the chart display. I have to say that I really like the overlay mode, and I love the automatic target tracking feature, which identifies and color codes targets based on whether they are moving towards or away from your vessel. At about $2500 for the hardware and software, this is an upgrade that delivers huge bang for the buck.

Here is a not-so-great picture of the stand-alone radar display in TimeZero.

We have not yet gotten around to the autopilot installation. That is planned for our second visit to Philbrooks, sometime in mid-August.