HELIX 7 SI can benefit from the upgrade XHS 9 HDSI 180 T xducer ...
https://humminbird.johnsonoutdoors.c...som-transducer
The upgrade xducer will not give HELIX 7 SI the 800kHz frequency but the longer SI piezoes will still give somewhat better detail than the stock SI xducer ...
HD vs Compact transducer
Rickie