Update please. I have been kicking around a similar idea except I want to drop my transducer between my pontoons. I will need to get it down below the prop wash of my trolling motor but able to raise it for transport. I have not been able to locate a tube hinge that will allow the cable to pass through. All that I have found are solid bodied. The diameter of the tubing is not as important as the hinge being able to pass thru a sleeve without binding. Any thoughts?