NMEA 0183 Fail + Great Sailing Weekend

I am the unfortunate soul who decided to take a brand new chartplotter and feed it converted NMEA 0183 data that was converted from Seatalk with a multiplexer. Heading is not getting picked up by the chartplotter.

Garmin GPSMap 820 showing heading but not picking up my NMEA 0183 heading data.
Garmin GPSMap 820 showing heading but not picking up my NMEA 0183 heading data.

The Garmin GPSMap is showing wind, true and apparent as well as depth and water temperature. I can see the heading NMEA sentence getting updated using the settings->NMEA0183->diagnostics view.

Garmin GPSMap 820 diagnostics view for NMEA 0183, showing heading
Garmin GPSMap 820 diagnostics view for NMEA 0183, showing heading

To make it even more annoying, a simple NMEA parser explains what it takes to parse the HCHDG sentence but Garmin’s brand new chartplotter does not seem to pick it up.

iNavX showing heading on both true and magnetic
iNavX showing heading on both true and magnetic
iNavX showing NMEA sentences with the same HCHDG that Garmin should be using
iNavX showing NMEA sentences with the same HCHDG that Garmin should be using

So why I ask is Gamin unable to do it when a pretty simple iPhone app is capable of parsing the same sentence into a compass heading? The funny thing is that I once reached out to Garmin because I wanted to work on their marine software because I liked Bluechart so much. Compared to iNavX I must admit that Garmin is not a good choice for getting NMEA data and AIS targets all into the same touchscreen, tappable view. They have a choice to take the data and send it to their Bluechart app and are losing a big opportunity to make the best navigation aid out there. iNavX wins but I’m not happy with raster charts. That’s why I like Bluechart so much, along with the tappable chart icons for objects like buoys, places to anchor or reefs. I feel a little more confident when navigating in the shallow waters with vector more than raster charts.

I have a chartplotter that has been upgraded thanks to the nice guy from technical support. Apparently Garmin normally charges $30 for sending an SD card with the update but since I was having issues with my NMEA heading and the update apparently had something to do with NMEA 0183 heading, he sent out an update card for free. I would have downloaded it but they only have Windows based updates and I’m on a Mac and haven’t gotten around to running a virtual Windows machine for this kind of scenario. Regardless, the software update didn’t do anything. I’m making this blog post to send to him so he can get his software engineers to fix the problem for me.

Since I don’t have a radar hooked up yet and I have iNavX working great on the iPad, I left the chartplotter off the whole time while sailing this last weekend.

Satori hauled to the wind in Puget Sound near Blake Island
Satori hauled to the wind in Puget Sound near Blake Island

My friend Brent and I spent the weekend out at Blake Island, sailing is great winds. We had anywhere from 5 to 20 knots with the most exciting moments in the evening while sailing on a broad reach towards Lincoln Park. We anchored in deep water and bounced around from the boat traffic so the next day we moved a little closer to shore. We still felt plenty of boat traffic, especially the big ones coming up from Tacoma past Vashon Island. Here is our track from Friday through Saturday.

Satori anchored at Blake Island
Satori anchored at Blake Island

Sunday was really wet and rainy the whole time. It became worse towards late afternoon but the sailing was still enjoyable. We did wing-on-wing heading home and I was having an issue with the jib backwinding on occasion. We were tracked from Blake all the way home. Here is our track for Sunday’s ride home.

Satori in a Puget Sound downpour, cruising at 5 knots
Satori in a Puget Sound downpour, cruising at 5 knots

I never managed to get the solar panels working so I had to use the portable gas generator to keep the batteries charged. We enjoyed warm water since we were pulling AC power and were able to connect as shore power. Also, the tiller pilot works great. It failed only when I would expect it to, like when the sails are not balanced properly on a downwind run or when there isn’t enough steady wind to keep it pointed straight. Also, I did try to do an entire lap around the island with the pilot but reverted to steering for a bit when things went awry. Once was because we were close to a lee shore and I didn’t feel comfortable falling off towards shore. A little too risky for me I guess.

I still really need to get the solar system running so I don’t have to use the generator (except for an occasional shower). Otherwise most of the other issues we had aren’t even worth mentioning. It was a great weekend to enjoy some classic PNW sailing in the Sound.

 

UPDATE:

After spending close to thirty minutes today in a phone conversation, it seems that I am actually getting the heading data but the screen that I expected to show it isn’t intended to show magnetic compass heading. If you have a Garmin chartplotter you might have thought that the instruments->compass view would show magnetic heading but it does not. The only place you would see magnetic compass is on the chart view when configuring the small corner displays and the compass rose around the icon indicating your vessel. I honestly didn’t even look there because…well, the compass screen should show magnetic heading. That begs another question; why would I want to show GPS heading in the compass screen? I don’t know what Garmin was thinking. Regardless, the issue is no longer and I can rest on the chartplotter problem. 

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