Thursday, August 13, 2015

Hacking Peregine

I haven't been posting as regularly as I'd liked, this is a summary of what went on in the spring and I'll be sending out a summary of the first half of our racing season a little later.

Peregrine spent the month of March on the hard at the Charleston City Boatyard. I did a little work, they did a little work and we launched in time for the CORA Spring Offshore Race, where kicked off the season with an excellent performance. I attribute our finish to a combination of the great work that City Boatyard did on the bottom paint and great crew work with several new people on the boat. The dolphins were out in force and the weather was made to order for us blowing 10-15 with 4 ft seas offshore.

Last fall I had several nervous moments when my 1980's vintage depth sounder started telling me it was 1' deep while we were in a shipping channel. Charleston harbor has more than its fair share of shallow water. While we were out of the water I decided install some new instrumentation, but I'm operating on a budget so I couldn't afford a tear out - upgrade. This post discusses the process of integrating our new Airmax (Garmin) DST 800 sender with the existing instruments.

Here are some pictures of the process of removing the old sender through hull. It was a less painful process than I anticipated and the new unit fit smoothly into place without any drilling or filling. At the yards recommendation the new unit was bedded with 5200. I was pleasantly surprised that the whole thing stayed dry after we launched.

The DST800 I selected was the NMEA 0183 version, I wanted it to be compatible with OpenCPN, which I run on my laptop.

There were two objectives to my project. First, that the sender signals would be available at the navigators desk for the plotter, PC and recording log. Second, that I would have access to the depth and speed information at the helm using the existing displays if possible to reduce costs.

My existing NMEA 0183 setup consists of a Garmin 76 GPS, a VHF radio with AIS and a laptop running OpenCPN. 

The layout for the new system will add the DST800 feeding the PC. The next piece of the puzzle is to expand our display options so we can see the output from the DST800 on deck, etc.