No, I don't know anyone with SI unit or di unit. The deepest waters will be 30-40 but it'll be mostly run in 5-12 foot of water.
spoke with humminbird again, they advise not to run the Ethernet cable next to the td cable. I'm going to check around and see if there are any products that may help protect against interference.
the way my boat is currently set up, it'd be a pain to remove the decking to run them seperate