Stern mount transducer on a Revo?

[pbb]

I've got a pre-lowrance-ready Revo, and I use a 1/2" pvc arm that mounts in the sail mount (so it's basically u shaped). I left one of the joints uncemented so I can swing it up and down.

I've thought about trying to make a mount on the rudder, but I hate it when I'm not paying attention and my line gets tangled in the rudder and I figure that will only make it worse.