
We would immediately set our speed to around 10 knots, turn in the direction that the person fell overboard (starboard or port), do a complete circle and end up where the person was.
At least that was the drill. Did it many times.
Unfortunately, the only time anyone fell over was while parked in Hong Hong. And he didn't hit the water.
There was a collection barge gathering all the crap we needed to get rid of (Used food, garbage, etc.), and he hit that. He survived.