When prepping my Dad's 60s vintage sloop for the Marion Bermuda Race, it was not feasible to rig the typical emergency steering tiller onto the top of the rudder post. Instead, we secured an 18" or so horizontal bar onto the rudder post. To each end of this bar we fastened a multi-part block and tackle. The control lines led thru fair eyes up to the cockpit. We tested it several times, including under robust sail, and it was remarkably easy to steer the boat, using the 5-part (if I remember correctly) system; pulling the lines on one side or the other you could easily steer the boat.

Thinking about it now it almost seems like a better method than the usual tiller-to-rudder stock arrangement: better ergonomics, no open ports to below, can theoretically be rigged and left in place, etc.