We put two in our cat and it is most helpful. One is a
Garmin the other a Navman. The
Garmin performs better. I think they're the same frequency....we have to turn the Navman on first then the Garmin in order for both to read. The other way around the Navman doesn't want to read.
One thing that might help someone....we ordered the Garmin
fishfinder and extension cable in from over-seas. The Airmar cable did not match the Garmin's factory fitting so we cut it off and splice together....wouldn't
work. Ended up figuring out the transom mount transducer (included in the package) had to wired into the system. So just wired it in behind the
helm. Doesn't do anything other then tell you the air temp, but what-ever is in that transom mount transducer is needed to make it
work.
Best - J