Electronics - Radar, Chart Plotter, Instruments and Pilot | Sailing Blog - Technical Hints and Tips - Sailing Television

Electronics - Radar, Chart Plotter, Instruments and Pilot

I have been in the middle of planning the instruments for the new boat. Most of it is sorted out now so I thought I'd give you an overview of the (nearly) final system.

First, regular viewers of our TV show will know I installed a Raymarine C80 and associated system a few years ago. To say I have been happy with the C80 is a huge understatement! I mean, all the Raymarine stuff works great, the autopilot was strong and quick and handled Two-Step very well, and the instruments were excellent too. But the C80 Plotter was a revelation!! It has an 8.4" screen which was a huge inprovement over our last plotter (with a small 5" screen). But the best feature is the integration with the other components of the system. I had not realized what it could mean to have information from the wind, speed, autopilot and especially the radar communicated to the plotter.

  • Wind: the C80 can display the wind as a yellow arrow blowing toward your boat - on the chart. This means you can instantly see the actual wind direction on the chart. For sailors this means all the calculations on which is the favoured tack is much easier.
  • Speed: naturally the plotter knows the boat's speed from the GPS, but it also gets the speed through the water from the knot-log sender. So the plotter can calculate what currents are affecting the boat as well. If you have entered a waypoint then it can also calculate the progress you are making toward that. The C80 can display a small arrow showing the direction of the current/leeway.
  • Radar: Here is my favourite integration feature of the Raymarine plotters. The radar image can be overlaid on top of the chart! It is actually quite difficult to do this from a technical point of view. On a big ship the heading doesn't change much, so the radar image can be simply set up to line up with the heading of the ship. But on a sailboat in perky conditions, the heading is changing quite a lot. So in the time it takes for one rotation of the radar scanner, the heading has changed. Without getting into too much detail, it is DARNED DIFFICULT to plot the radar image on top of the chart. But the Raymarine system does a good job. So good in fact that it can make accurate calculations on a single radar target... which leads to my next favourite feature!
  • MARPA: this is really a result of the radar integration but deserves a heading all to itself since it is SO COOL! MARPA means mini automatic radar plotting aid. This is an amazing tool and really made us feel safer at sea whenever there were big ships around, and especially at night. Basically it allows you to identify a ship on the radar and have the MARPA track that target - giving you the direction and speed of the target. Marpa will draw an arrow on the chart showing the course of the ship! It also calculates the ship's speed, and whether it will pose a threat to you! It really is hard to explain just how great this feature is. I have featured it a couple of times in our TV show since I am really convinced it is a huge safety and confidence plus for anyone who gets out in open water where there are ships. Very cool! Here is the link to a good description of this on Raymarine's website For this to work well you should have a gyro compass - luckily one is built into the G series of Raymarine Pilots. We had the S2G on Two-Step and will get it again on the new boat. Bringing us to the next point...
  • Autopilot: the plotter gets exact course and heading info from the autopilot. Put a waypoint on the plotter, press goto, and the autopilot can be engaged to steer along the track to that exact point. This means it will use the plotter and GPS to insure it doesn't deviate from the line due to currents and leeway. This is not possible if the autopilot doesn't have some level of integration with the GPS. Of course the best is to have a plotter since you can then plot the position visually on the chart - and just go there.

So here's the list of electronics we are getting for the new boat.

Chart-plotters - One E120 for the nav station. I never wanted a plotter in the nav station on Two-Step since you can't see out. But the new boat has a pilot house and it will be just perfect there. But I also want one outside for when we're sailing. So we are also getting a E80 - looks exactly like our trusted C80 but is able to network with the E120 below. This means we just have one Radar antenna, and one chart chip with the navigation charts on, but can display the info on both displays. This is a picture of the nav station on a Southerly 42 like ours with the Raymarine E120 in the nav station. I am still trying to figure out where to put the E80 display. It will be in the cockpit somewhere but I'm not sure where. My plan is to wait until we have sailed a bit to see where it would be best. Two obvious spots are up under the dodger (sprayhood) where its visible from the main cockpit, or back on the table where it would be easier for someone at the helm to see.

Autopilot - Raymarine S2G Smartpilot with two control stations. One in the nav station as pictured above and one at the helm. We are also getting a remote for the pilot in case we are sitting forward from the helm.

Radar - 2KW radome will be installed up the mast. (Raymarine also). This can do the Marpa functions since we have the Gyro series autopilot controller - S2G above.

Instruments - Raymarine ST60+ series wind, speed and depth separate instruments. Also a graphic display which can repeat any of the info on the "bus". This will be at the nav station - although strictly speaking the E120 plotter can provide the same info and more - its convenient to have it already up on a dedicated repeater.

Lifetag - Raymarines new safety MOB system. More on this in a future blog.

AIS - WAY COOL!! I have been so looking forward to having AIS. More in a special AIS blog!

Thats it for now. I'm off to plan the battery/genset etc.


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