I am doing a multi-season upgrade to more modern sailboat nav electronics.
Currently have:
--Garmin 741xs Chartplotter with Radar, nothing else talking to it, installed a couple of years ago.
--Raymarine ST60+ Tridata Depth/Speed/temp with transducers directly connected.
--Autohelm ST6000+ head with Type 300 computer and below decks actuator
Right now none of the above are interfaced. Now, my Raymarine speed impeller has bit the dust. I want to replace it with a speed impeller transducer that will talk directly to the Garmin 741xs, and while I am at it, put in an depth transducer to talk directly to the Garmin 741xs.
But...I'd like to keep the ST60+ to repeat the Depth/Speed/Temp rather than spend over $500 for a new display that will do the same thing. I'd also like to have the Autohelm interface with the Garmin.
I'd like the flexibility to add wind and AIS in the next year or so as well. Is this all doable, or am I asking for a problematic and messy jumble of wires?? I'd like guidance on the least expensive and most effective way to do all this.
I would like to have the ST60+ repeat the
Most simple way to achieve your initial desires is to replace your speed transducer with identical product, and use the Raymarine "SeaTalk 1 to SeaTalk ng Converter Kit" to connect to your Garmin chartplotter to your seatalk sensors and displays.
Look to Garmin for your AIS purchase
For exceptional apparent wind measurement, use the Airmar WS line of ultrasonic wind product
You didn't mention it, but a NMEA-2000 connected solid state compass is a nice addition.
You didn't mention it, but take the opportunity to take GPS data into your VHF radio, so that Rescue 21 functionality works when pressing the red button.
For autopilot ... don't know the answer.