Some more information has been reported via Facebook. Rush had once seen about a ten foot tiger shark near the red mark on the sat. image when kiting in the area.
Austin related that the shark attack happened a few hundred yards to the north northeast of the red mark in about 8 to 10 ft. of water. It was near sunset and fish were being cleaned in the area. That is a bad combination increasing the odds of problem shark encounters. Regular fishing cleaning in some of the Bahamian islands reliably bring in feeding sharks daily. Not sure if that is the case here or not.