here. "Hit the water cleanly" could mean one of two things. It could be that the Editor just happened to roll low falling damage and explained it that way, as flavor text. The other way is that a game mechanic came into play here, either the Editor allowing a save vs. science for no damage because it was a controlled dive into water, or perhaps the player using a stunt like Hit Water Cleanly (which doesn't exist yet, but could).
Player tip -- when playing in the Mythic West, always know the warning signs of a poison water hole.
(Scans courtesy of Digital Comic Museum)