RedactedNarrative: Watercraft was pulling a tube occupied by two children and an adult. There were two other people, in addition to the operator, in the boat. They are the children's parents and they were acting as spotters. The boat was paralleling the shore going south. The operator was unaware that the tube was outside the wake on the left side. The spotters did not make him aware of this. The tube struck a boat which was on a lift. The three occupants on the tube were injured. All three were wearing life jackets. The occupants on the boat were not wearing life jackets. There was minor damage to the boat on the lift. Alcohol was not a factor.