RedactedNarrative: Vessel 1 was traveling about 20 mph towing two females on a medium sized round tube. When Vessel 1 Operator saw a large wave, about 3 feet tall he headed for it. The boat went through the wave just fine but when the girls on the tube hit the wave one fell off as she was holding tightly to the tube.  When she hit the water she kept holding on. The force broke her left arm. Vessel 1 Operator turned around right away to pick up the Injured tuber. When Vessel 1 Operator tried getting the injured tuber into the boat, she stated that she could not lift her arm.