Marine Electronics, A Mess…
Over the past few months I’ve been doing a bunch of research into different marine electronics and how they can work together. My goal is to begin updating the oldest parts of our boat’s systems and then slowly add more advanced functions over time. The first items I want to tackle are the Depth and Speed sensors and displays. I’m pretty sure they are original and the Depth gauge is already acting flaky. On our last trip it almost stopped working completely for a couple days near the end.
Now I’m a pretty technical person, my job is mostly made up of designing and implementing (then supporting) complex computer systems, but the Marine Electronics industry has pretty much made it impossible to really implement a simple system with all the features I want at a reasonable cost. I find it completely asinine that I should have to pay about $700 just for the transducer to keep tabs on the depth and that doesn’t include a display to see the depth. I also have to buy the display from the same company that I purchase the transducer from, so in the case of Raymarine, it’s another $500 for the display. So here we are at $1200 to know the depth. Part of the problem is that the transducer and corresponding “Digital Sounder Module” are designed for Fishfinding duties. But I don’t give a hoot about the fish, I just want to know when a rock is about to rip the 3500 pound lead keel off the bottom of our boat. Problem is you really can’t get JUST a depth sounder, it’s “High Definition 600 watt, multi frequency high speed fish detection” or nada. And it’s not just Raymarine, they are all pretty much the same, and the cost is all about the same too.
NMEA0183 is a networking standard loosely based on RS232 serial from what I can tell. NMEA2000 is newer and is based on CANBUS which auto manufacturers use in cars. These are the “industry standards”. But it’s nearly impossible to buy anything that is directly compatible with either of them. Raymarine, Lowrance, Faruno and Garmin all have their own proprietary networks that only their own products work with. Raymarine has 4 of their OWN networks… SeaTalk, SeaTalk2, SeaTalkNG, SeaTalkHS. None are compatible with each other. Technically Seatalk2 is fully NMEA2000 certified, but the cables are different. You can cut the ends off and wire them together by hand and it will work just fine. All of the manufacturers are going to NMEA2000 compatible devices, but they all have their own connectors for the most part meaning you are buying adapters from them, or making your own connections with a soldering gun.
The more I read on blogs, reseller sites, and manufacturer sites, the more I have decided that buying NMEA2000 compatible devices is the only way to fly. However it just got harder. While the Raymarine ST70 full color Multifunction display can display pretty much ANY data from any NMEA2000 compatible device (depth, speed, gps, engine, etc) it apparently cannot configure/calibrate non-Raymarine devices. This means that if I were to use an Airmar NMEA2000 Depth transducer, the ST70 would show the depth, but it wouldn’t be correct because I would have no way of calibrating the Airmar from the ST70. It turns out that the “Calibration sentences” are not part of the NMEA2000 specifications because manufacturers believe they are competitive secrets. I’m still researching how to handle this problem but it makes it tough to finalize any purchasing decisions.
Phase 2 of the project would have added a Raymarine C70 or C80 display for chartplotting. Plugging it into the NMEA network I had built for the depth and speed would have made that data available on the C-series display. Phase 3 adds a new Autopilot integrated into the same network making even better use of the C-Series and other data. But if I can’t get even the simplest network to work for depth and speed, how the hell can I expect that I’ll be able to successfully integrate the Chartplotter and autopilot later.
I really wonder when electronics manufacturers will wake up and realize that rather than locking in your customers through artificial limitations, they should make a best of breed product and make it compatible with everything else. Open Standards and Plug and Play is the way of the future.. Get with the program!