In this video, Air Tanker 131, a C-130Q, is seen making two drops with water — instead of fire retardant — on the Mud Lake Complex of fires in Big Cypress National Preserve in south Florida. This is an unusual tactic for most large air tankers that normally drop retardant. It was a direct attack on the edge of the fire, rather than being offset as they would usually do with retardant. In the United States, federal policy does not allow retardant to be dropped near water. Many areas in the Mud Lake Complex were near wetlands.
Air tankers that can skim over the surface of a lake, scooping water to refill their tanks, usually drop water instead of retardant. Those aircraft include the Air Tractor Fire Boss, CL-215/415, and the Martin Mars.
Coulson Aviation attached a GoPro camera to the belly of their C-130Q to record the video in May, 2015.
If you are wondering how far water dropped by an air tanker spreads out laterally, check out this video of a scooper dropping on a vehicle fire in Canada.