RedactedNarrative: Unit 1 was traveling West on Lake Bowen towards the I-26 bridge at approx. 15-20 mph when he struck an anchored vessel (Unit 2) who was fishing.  Unit 2 was facing East.  Subject of Unit 2 was standing on the front of the boat casting towards the West when he heard Unit 1 getting closer.  Subject on Unit 2 turned around and was struck on the starboard side by Unit 1 on the starboard side.  Subject on Unit 2 was thrown overboard into the water.  Subject on Unit 2 had a Type V wearable PFD but was not being worn.  Subjects on Unit 1 stated the glare off the water from the sun made it hard to see and never saw Unit 2.  Subjects from Unit 1 assisted man overboard back into the boat and both Units went back to the dock.