b19000

Try the RayMarine Element 7HV. If you are patient they have been being offered in your price range fully equipped (e.g. Navionics, transducer and sonar). I think the lowest WestMarine let them go for was $499 last fathers day. Of course Ultimate Passage always seems to follow suit as well as BOE Marine. Can't beat RayMarine's 3 year warranty. On a kayak I would go with a Garmin STRIKER Plus 4.

Airmar advertises their transducers are compatible with RayMarine, here is the rest of the story. "The Element series (both the -HV and -S) do not support any AirMar transducer offerings and in the Axiom family you have to go to the Pro-RVX to support any AirMar Chirp offerings, but the only transom mounted AirMar chirpo transducer that we support is the TM265LH" I had a difficult time pulling info concerning the following Raymarine transducer, here is the rest of the story. "The Element HV (using the HV-100) and Axiom RV platforms (using the RV-100) both contain a traditional color graph channel we call Sonar that chirps in the high frequency range. Depending on your depth that sweep will range between 170khz-210khz." Point is, Humminbird (Item # 710282-1) CHIRP Frequencies sweep at: Full: 150-220 kHz, Narrow: 180-240 kHz, Wide: 140-200 kHz. Garmin (010-12405-00) CHIRP High Wide sweeps (150-240 kHz). I gather it cost more to make transducers that sweep a larger range, and this range allows increased target separation.