The only way to do it is on water. This is what you need to do:

Get a sand bag or something similar to weigh down the transducer where you
think you want it, and flood the bilge so it covers the transducer. Now
motor around and look at the readings. If they seem spotty, or inacurrate,
then move the puck to a different spot. Keep doing this until you're happy
with the readings, and mark the spot. Now you can work in your driveway. :-)

Remember to use SLOW setting epoxy (4hrs or more) when you glue the puck in
place, and use a lot of it. The slow set allows most air to escape while
curing. Air is bad when between the transducer and water.

Good luck.

--Mike

"LarryT" wrote in message
.. .
I plan on installing a depth sounder with a in hull puck transducer. Has
anyone installed one of these and if so can it be tested out of water? I'm
going to install it on my boat in my driveway and want to test the position
before I epoxy it down.

Thanks