Excellent question! Next week we're going down to Cabelas to see these units for themselves before buying. If I understand correctly, the "SV" model suppose to have all the bells & whistles, including chirp. But right now I'm so confused I don't know which has what! LOL!
I will say this....from talking to a lot of good fishermen in this neck of the woods, they advocate strongly for the SI feature. Having never used one myself, it's anyone's guess.
Last edited by Crestliner08; 03-02-2017 at 01:48 PM.
Reason: Clarification
"A voyage in search of knowledge need never abandon the spirit of adventure."