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Instrumentation and Electronics

Posted on Tue 21 April 2009 in Geek, Projects, Systems - Electronics

I have some older electronics on the boat which draw a lot power, have horrible or no displays and I'm geek I have to have the new newness. Here's a brief overview I wrote while I was eating lunch to get some of my thoughts written down so my mind would stop racing. As a general rule, I've come to view the overall system in two main sections.

The general purpose NMEA 2000 bus for gathering a displaying information via multi-purpose and multi-vendor displays and data sending units. E.g.: weather, dc usage, wind, location, etc.. These components all should interop with the exception that they need their vendor specific display for configuration. These items feed into the Navigational Components as well as other systems like the DSC on the VHF and to the PC for other applications as well like SSB position and weather reports.  For the General Purpose instrumentation I plan to use Maretron components and one DSM 250 (color) display in the nav station for configuration of those devices. We will also have one or two multi-function displays in the cockpit. I'm not yet sure what brand or model. I would include engine sensors in this category but I have no plans to wire up my 1981 Weterbeke 58 (probably can't) and I'm not currently planning on doing a repower. The sending units will include:

  • GPS100 GPS (1)
  • WSO-100 Wind and Weather (1)
  • SSC200 Compass (1)
  • DCM1000 DC Monitor for each battery bank and Solar Panels (3)
  • USB1000 USB Gateway to connect to PC (1)
  • DSM 250 color display (1)
  • TLM100 Tank Level Monitors for both fresh water tanks and the diesel tank (3)
  • NMEA 0183 Adapter for connecting VHF to Network (1) (maybe the GPS can do this automagically)

Beyond the general purpose systems, the Navigational components (RADAR, Chart plotter, PC Nav Software and Autopilot) must all be of the same brand and compatible in order to get ChartRadar overly on the plotter and the PC as well as single point control of the auto-pilot (i.e, the ability to change course from the PC Or the Chart plotter. To that end, I plan to go exclusively with Raymarine. I'm basing a lot of this on the survey results from the SSCA ( >50% of member surveyed use Raymarine) and hands-on experience at trade shows. I will be using the Navionics Gold cards for charts. I see no need to have the 'looks cool' 3D bathospheric views since they are based on such minimal data especially where we plan to Cruise (S. Pacific). I'm less resolved about what models on these items but the basic components will be:

  • Chartplotter - I'm guessing the C120 widescreen, but I need to dig into the differences. The E does not yet appear to be any better for my needs than the E.
  • RADAR - 24" HD radome model. Big decision here I think is 2kw24nm or 4kw48nm.
  • Autopilot - Need to think this through more. Not sure how this and the Capehorn windvane will interact yet. We might be able to use a tiller autopilot and the windvane quadrant... save some \$ and could afford to carry a full spare maybe... ??
  • Depth Sounder Fish Finder - This is just for geeky fun. I like the idea of being able to see contour information, not really for fishing. This integrates with the chartplotter and PC Software.
  • PC Software - Raytech RNS. Rosepoint Nav really has the best software, but I want a dedicated charplotter AND a PC and they have no solution for that.

[Open Issues]


I think I'm settled on Maretron Mid size cable for the backbone and their smaller cable for all the drops to the sending units and non-Raymarine components. I’m guessing that I will run the main bus from starting at the spreaders on the main mast and ending at the spreaders on the mizzen mast. I think that will be far enough to let me run the lighter weight cables to the mastheads where needed. The run from the main will go throughundernear the nav station and then along the foreword end of the cockpit which before heading up the mizzen, again this will let me add displays and reach the batteries. 

I'm not sure if I'll need a separate smaller bus for the Raymarine Seatalk HS network. I think I do since at a minimum the RADAR and chartplotter and PC don't talk over the NMEA 2000 bus.


We will add AIS closer to our departure time. I'm 99.9% sure I'll go with Raymarine again with the thought that it is all about the ability to overlay the information.

The next step is going to be to draw this up and start taking to sales reps here in Seattle looking for the best prices and service.

If you have any thoughts on my my overall plans feel free to chime in. I’m particularly interested if there are any known Raymarine Maretron interop issues.