Your question is a little ambiguous.
It could be taken as, ' How do you put your boat down without leaving the rudder seemingly vulnerable? '.
Or,' How do you run up the beach with your boat at say the end of a race without hurting your rudder by dragging it?'.
I for one have no problems with just resting it on it's side with the rudder on the ground.
I suppose if you really wanted to worry about it, dig a hole for it .
As for dragging it up the beach, I tend to want to keep my boat in good nick, so I'll pick it up and carry it if that is what i required. I'm more concerned about scratching the hull than the rudder though.
I've felt my rudder drag through sand in the shallows and near the beach enough to not worry about just resting it on the ground.
If you mean, when you approach the beach, and you feel the rudder in the sand and then get out and still have a considerable walk through very shallow water, I just pick it up by the footstrap and slide it along beside me, or let it float along itself and give it a push every now and then to keep it going, no weight in the ski, very little force on the rudder if it did hit the sand a few times.
The fact that you see no manufacturers warnings or posts on here about damaging a rudder in such a way, pretty much means that it is really a non issue.
I've had mine drag over the top of a small rock/reef? and it didn't even leave a mark on the rudder.
Water is pretty good at allowing the ski to move out of harms way.
Now you can curl up and go to sleep and dream of those terrible waves that are waiting to smash your hull.....
Follow the path of the independent thinker. Expose your ideas to the dangers of controversy. Speak your mind and fear less the label of 'crackpot' than the stigma of conformity. And on issues that are important to you, stand up and be counted at any cost.--- Thomas J. Watson