My boat came with real old instruments - Datamarine Wind, Speed, and Depth. I added a chartplotter with fishfinder, and a VHF with AIS radio.
I really like having the wind display. It's not entirely necessary because I still use the telltails on the sails for trimming and I can feel the windspeed enough to know when to reef, but it's nice to see the wind angle when the bimini is up and I can't see the windex at the top of the mast.
Regarding Speed Through Water (STW) aka paddle wheel speed from a transducer, vs. Speed Over Ground (SOG) aka GPS speed, if you are in an area without current, I think that SOG is all you really need. If you are racing, STW will react faster to wind shifts, but it's not all that important. I sail on the Long Island Sound and we have significant currents. So, having both allows me to see what the current is doing RIGHT NOW and helps me a little. The paddlewheel gets fouled frequently so it's a pain keeping it clean.
One last thing, if you do go with NMEA2000, look into trying this for wind speed, direction, etc.:
Maretron : Marine Electronic Instruments
No whirlybird things to break, easy integration, etc.
Let me know how it works, I'd love to have one!
BarryL, I was thinking about the fish finder route and just going with a mechanical windex. One of the neat things about the electronics windex plus GPS is the ability to calculate actual wind though being new to sailing I'm not sure how useful that would be to me at this point.
Our sailing season is fairly short up here on the Finger Lakes and water temperature isn't important to me so the fewer holes I have to put in the boat the better, so it's nice to hear that the transducers can shoot through.
At the risk of maybe getting off topic a bit. What is your opinion on GPS vs through the water? Which do you find is more useful? Also what are your thoughts on the usefulness of actual wind vs apparent wind?