2K Transducer for CP470

[davej]

Hi Chuck, and all,
I am to the point of selecting and purchasing my transducer. I fish the gulf stream (trolling) and am also planning to do some deep drop bottom fishing. I have the cp470 and would like your recommendation on a transducer to get the most out of my sounder. I have read through some of the posts, and did not get a clear sense of what is best. I would prefer a single unit with dual elements, thru hull, but am not limiting my options. Performance is the end goal.
Thanks in advance