RedactedNarrative: Watercraft was towing a tube. The boat was in some weeds. The operator went in reverse to clear the weeds. The person on the tube was pulling the tow rope so it wouldn't get caught in the prop. When the boat was clear of the weeds, the tuber told the spotter to tell the operator to go forward. While the boat was slowly moving forward to tighten the rope, the tow rope was wrapped around the tuber's finger. When the rope tightened, it severed the tuber's left index finger below the knuckle.