Actual. I don't want to do math when in a pinch. Also, I anchor in places where there may only be 1 or 2 ft. below my keel at low tide. That renders the depth warning useless on most systems.
I don't follow Tim's post above
I know that I draw 5.7' I set my Fishfinder to read actual (no Keel offset) so that I can compare easily with the depth soundings on the chart. I also have the shallow water alarm set for 8'...