Tachometer is for the motor. Speedometer goes on the boat, but use a handheld GPS instead.
For a tachometer, Google "tiny tach" : http://www.tinytach.com/tinytach/index.php
Thanks for the Info, I have a Tiny Tach, works great. I just see that there is a Speedo on my new-used boat and wasn't sure if it was a boat thing or a motor thing.
