s/v Jammy

s/v Jammy

Jammy was a 1979 US Yachts 295 sailboat that graced my life from 2004-2015. She and I had many years of adventures and projects in Seattle, and around Puget Sound. I sold her in 2015 to move up to a larger sailboat, Grace.

When I bought Jammy in 2004, she had basic instruments that were not reliable, original engine, and old sails, but she was sound as can be, sailed fast, and had tons of potential. I set about a 10+ year endeavor to learn more about the inner workings of a sailboat, in particular marine electronics, engines, and electrical system.

Photos of Jammy and projects are available here.

Over the years, I did major work on her – everything from completely replacing the entire electrical system, to adding over 50 NMEA 2000 network devices to a brand new network I built from scratch. Many of those adventures are cataloged here on this site, but many are not. Over time I hope to document those that are missing.


Below is a partial list of projects and updates I did on Jammy over the years.

  • Doyle sails with stack-pack
  • Engine repower / replacement
  • Complete electrical system rewire/replacement
  • NMEA 2000 bus throughout boat
  • CradlePoint and then Pepwave WiFi / 4G router
  • MasterVolt charger
  • Garmin MFD
  • Multiple VHF radios
  • Multiple AIS Class-B transponders
  • Simrad NSS and then NSE network
  • B&G Zeus(2) network
  • B&G Triton displays
  • Maretron instruments (many)
  • Fusion Marine Radios (two)
  • Raymarine i70 displays
  • BR24 digital radar
  • Navico WM-2 Sirius Weather/Radio
  • Remote Commander for AutoPilot (WR20)
  • Actisense gateways to various devices
  • Simrad TillerPilot autopilot
  • SignalK server
  • LED replacement of all interior and exterior lights
  • DMK Yacht instrument
  • Front Panel Express panel replacements
  • Parker fuel polishing system

I’m sure I’m forgetting a few – I intend on adding more details as soon as I can.


Jammy had an extensive NMEA 2000 and otherwise network on her. At the height of the design, there was over a megabyte per minute of data being generated by the NMEA 2000 bus alone. The bus itself had over 40 devices living on it, and that didn’t count the Ethernet, wireless, and non marine focused networks. She was used by multiple vendors including Maretron, DMK, Navico, and SignalK to debug their software/hardware that tended to explode or have issues at these levels of traffic.

Below is an example of the network from 2012. Click for a larger version to zoom in on.

Jammy Electronics

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