RedactedNarrative: While skiing, the Injured person moved outside of the wake area and due to the larger waves lost balance and fell.  When the Injured person lost his balance and fell he did not immediately let go from the tow line.  Observer in vessel observed the fall and the Operator returned to retrieve the skier.  At that time, the Injured person reported that he had pain in his left upper arm.  The Operator and the Observer assisted the Injured person into the boat.