Baja, I am having a similar issue, have someone wiggle the wheel and watch where the cable enters the power unit in the back.... It the cable housing and nut moving back and forth?

I'm not near the boat for a few days, but as I remember the cable is tight in the rear. The slop is in the wheel before the cable even moves.

My cable is tight too... However, where the cable screws into the power unit in the back is where I have movement. The cable has a female threaded collar (nut) that the is fully tight but the male threads that are part of the power steering unit move an inch or so when you wiggle wheel causing play. The entire unit is not moving, only the part with the male threads that the cable is threaded on to (again, the nut is fully tight)

Anyone have an idea what my issue is? Do I need a new power steering unit? Is there something that needs tightening on my current unit?

You will never get rid of all the slop with a cable system, never. You need to go full hydraulic to have zero slop.