I can't get a picture but it is just a cable that winds in or out and moves the steering cable.
just keep greasing it and working penetrating fluids into it. over time it will loosen up but if its bad it could take a while to free up.
in a worse case you may need to pull the motor and separate the swivel arm and clean it out, I don't know if its going to just be build up in there or if the bearings might need replacing but that's where your problem is
I never thought about bearings. Being in a salt water area is bad news for maintaining stuff.