plenty of experts here who can talk about transducers, frequencies ect, but the most important thing I never considered when buying a separate sounder was the fact that the sounder and GPS do not speak to each other. (ie: when I see lumps come up on the sounder you want to be able to instantly plot the GPS mark using the sounder rather than go back looking for what you just passed over. I've got a furuno sounder and a lowrance HDS7 chart plotter, I don't think there is any way you can link the two?

 Thanks dougie- cant believe I've been doing it the hard way for the last 6 months. I'll read up on this

yellow furuno to yellow lowrance and green furuno to blue lowrance.

In the furuno menu go to NMEA 0183 select in/in and out off and they should auto configure.

The furuno will recieve gps data from the lowrance but not the other way round. You can mark spots with the furuno and then manually enter it into the lowrance..

I have had the furuno fcv620 with the P66 transducer and that worked great and even better with the TM260 (1kw Transducer). I now have the fcv587 and the TM260 and love it although I haven't spent much time with it to test its full potential. I have read about people using this combo upto 600m and more.

for a stand alone sounder you can't go wrong with a Furuno if it fits the budget they are very popular with the recriational guys and for a reason. Also get the book written by John Adams 'how to use an echo sounder/ fish finder'.... well worth it...

Cheers..