I installed a flush/dash mount Hummingbird HDR600
http://starmarinedepot.com/Humminbird+HDR600.html ) on the boat this
afternoon. The installation (including transom mounted transducer) was
fairly easy.

I will be fine tuning the unit while on the Lake tomorrow and in between
tubing and swimming.

Does anyone here have this unit and if so, can you offer any advice on
tweaking it?

Thanks in advance for your responses and advice. ;-)