Robinetta does tech

The last bits of 1970s technology have been retired for this season. I repaired the Seafarer 3 echo sounder twice last summer and finally decided to replace it. The old VHF radio works fine but prompted by the surveyor Alison wanted a modern DSC unit.

The Seafarer 3's transducer died a few years ago and Nasa Marine still sell a compatible single frequency 150 kHz unit. It is embedded in the foot-thick oak keel so I didn't want to change it again. I could have installed one of the current equivalent Nasa head units but I wanted the chance to remote the depth indication. The Actisense DST-2 can drive the transducer and a log and temperature sensors and outputs NMEA 0183. It can also be connected to a PC. For now I've put it in a visible spot but once I know what I want to do with it I'll hide it. I wired it to the Garmin GPSMAP 450 chart plotter in the cockpit and now we get depth in metres without having to peer into the cabin. The new ICOM M323 needs latitude, longitude and time to do its DSC mayday magic and that comes from the Garmin. It can also send the position of other ships obtained by DSC position requests to the plotter, but I don't expect to use that so I haven't wired it up. Finally the plotter is also connected to the Simrad tiller pilot so in theory it will steer to way-points. I'll try that sometime. The tiller pilot can steer to wind with the right input. I might do that at some point, but we don't have a windex yet. The cabling will get a bit tidier.