Do you know where she’s been and what she’s been saying?
Now there’s an inexpensive way of capturing your NMEA 2000 (N2K) based voyage and engine data for post processing. While most multi-function displays can log a track of your voyage, you have to remember to manually start a track. These tracks also won’t typically include other data such as wind speed, depth, RPM, or engine hours along with the track. Russia’s Yacht Devices has recently launched a voyage recorder that does all this in an inexpensive way. At just US$189 with free shipping, it even includes connectors for Seatalk NG or DeviceNet. You’ll need an open spot on your network to plug it into, it can’t be swapped for a network terminator like Yacht Device’s other products can.
Ben over at Panbo wrote a good article last July about Yacht Device’s barometric and temperature sensors that also plug directly into a N2K network. Those products have a pretty crazy configuration routine that I won’t rehash here. There are also new products on the way.
Yacht Device’s next product (due in March), will be a US$99 16 character x 2 line text display that plugs right into the N2K network so that you can see engine or other parameters in a remote location on your boat. I’m told that after that the company will launch another sensor, this time voltage sensing of two battery banks. If they make a fuel tank level sensor like Maretron’s TLA100, I’m buying two! Stay tuned…
Yacht Device’s temperature sensor is apparently popular. People are creating thru-hull transducers out of them (as shown in the photo above). The voyage recorder is more logical to configure though. Slide in a Class 10+ Micro SD card (format as FAT32), then plug the recorder into the network and walk away until you need to analyze your data. You can optionally change the values in a configuration file on the Micro SD card for “covert operation” (From Russia with Love?). You can also exclude AIS data or up to 5 other PGNs (data types) if you don’t want to risk filling up your Micro SD card. If it does fill up then it starts overwriting the oldest data. Unless you are in an area of lots of AIS targets, this isn’t likely during a season of cruising.
After that you set and forget until it’s time to find the card and plug it into a computer. That is if you can access your network cables in that rats nest behind your helm! I would prefer a bluetooth option with a smartphone app, but that greatly adds to the software development costs and ultimately the final price of this kind of device. Perhaps an add-on for the future?
I can see this product being useful for charter operations who want to see how their boats are being used, or for commercial vessels who need to keep logs for legal reasons and want the data to back them up. For the recreational boater it can just be fun to share out your voyages and poke around through all the data on your network for anomalies. Perhaps you’ll find data you didn’t know was there. For marine installers this could be a handy product for network trouble shooting.
Yacht Devices says that the product captures all N2K data but not NMEA 0183 data which makes sense because they use different wiring. Having said that, the Raymarine C125 multi-function display that I own will gateway certain inbound NMEA 0183 data (e.g. depth) across to the N2K network. I am told that this forwarded NMEA 0183 data would also be able to be logged by the voyage recorder. I’d like to test this theory myself though.
So now you’re back from an adventure with Micro SD card in hand (it’s tiny so don’t lose it). You want to take a look at the data you captured. Yacht Devices provides a free utility called YDVR converter for Mac, Windows and Linux. You can create tracks in a variety of GPX formats for import into Google Maps or other programs. You can also create CSV files for further processing by spreadsheets or for custom integrations. A printable logbook can also be created using your own custom template which is pretty cool. There is also an XML export option for OpenSkipper and an option for Signal K format.
Signal K is still a work in progress so this conversion utility will need to be updated while the format sorts itself out. OpenSkipper (Windows, Linux) will apparently allow you to decode N2K messages and also replay your recordings while providing a pretty decent log viewer. I didn’t test this functionality because I only have a Mac. If you do, please post your thoughts below.
There are no “unit of measure” options for statute miles or mph when you convert the data. This probably isn’t a big deal because you can choose between nautical miles or the metric system which are more common for boaters. One of the challenges of creating the CSV file is that the units associated with the data aren’t included in the output file. You need to manually keep track of the chosen units when you convert the raw data to CSV with YDVR converter (the column heading just says Depth). The bottom line on this software is that you need to be computer literate to get the most out of it. Beware! Like all software I hope it will improve over time.
I played around with converting the sample data, creating GPX files that I then imported into Google Maps. Google Maps has a nice feature that allows you to upload multiple data sets and then turn them on and off as layers for viewing. What I hadn’t realized was how important it is to choose the right data frequency for your voyage and speed of vessel. The above track was for a sailboat on a 5 hour 36 minute journey doing an average speed of 3.8 mph. I only included data every 20 minutes to make the map look pretty. You can see from the summary that Google thought the journey was just over 5 hours at 2.5 mph average, for a distance of only 12.4 miles. Actual distance traveled was 21.5 miles. Sailboats don’t travel in a straight line for long!
The data opens nicely in Google Earth which seems to better support the extra data types present in the GPX file. Google Earth really is mind blowing software. You should check out the new virtual safari, it’s a lot of fun. I wish Google had marine charts! Navionics should think about allowing their free Web App to import GPX files.
By increasing the frequency to once a minute or once every 10 seconds the accuracy improves greatly. If you were in a powerboat you might want more frequent data because you are moving much faster. The map starts to look really crowded when we show data every 10 seconds though. Google Maps has a 5 MB limit when uploading GPX files so you may need to omit some data. The YDVR software makes this easy with frequency settings for seconds, minutes, or hours, all fully configurable.
I’m of the opinion that the voyage recorder provides great value. It really is quite the swiss army knife for data recording. I love that there is support for the Signal K format! Yacht Devices joined NMEA in December and hope to have certification in the next few months. It seems they are committed to developing good products. I look forward to seeing what’s next!
– Safe Boating –