RedactedNarrative: On April 9th at approximate 0100 hours Unit 1 was traveling Northwest across the Charleston Harbor towards the Cooper River. OPERATOR1 was traveling an estimated 25mph using a GPS. Unit 2 was a lit floating dredge pipe that was positioned across the entrance of the cooper river. Unit 1 collided with Unit 2 throwing all 3 occupants out of the vessel. All occupants were recovered and no injuries were sustained. Lighting from the city was thought to have interfered with the visibility of the dredge pipe.