I too have a full keel
boat. Brianlara is on the right track about learning
to use, not fight, your propwalk. To go astern, get started in reverse, and occasionally kick the stern back on course with a quick shot of forward with appropriate rudder
angle, quick enough to avoid killing all of your sternway. To turn the boat around in close quarters, do as just described, but use the opposite rudder
angle when you kick the stern over. If you have a right-handed prop, you will turn in a clockwise direction.