RedactedNarrative: Operator1 told me that his vessel sank abruptly and without warning after putting the vessel in reverse near Molasses Key. Operator1 told me that he had left his residence approximately two hours prior where he keeps his vessel in the water and tied to his dock at his residence. From there, he exited Sisters Creek channel and headed south towards the reef line to look for dolphin fish but was unsuccessful. He then proceeded back into shore near Molasses Key where he would anchor his vessel and scrub the algea growth on his vessel. Upon finding a place to set anchor, Operator1 put his vessel in reverse where it immediately began to sink. Operator1 explains he had only minutes to exit his vessel. A good Samaritan vessel came moments later and picked him up where he then called FWC for assistance. There were no other persons on the vessel to corroborate Operator1's vessel and the good Samaritan vessel passengers could not provide valid witness statements.   
  
  Capt. and I assisted Operator1 with contacting  a commercial assistance/salvage company and involving his insurance company via phone. Capt. made contact with the operator of Tow Boat U.S. and coordinated for them to begin the salvage process. At the time, there was a sheen of red diesel fuel coming from the sunk vessel. At that time the sunk vessel was laying on its starboard side with its stern laying on the sea floor and the bow raised approximately 30 degrees leaving parts of the tower console and out-riggers above water.  We took Operator1 back to his residence via water so that he could contact direct with the Tow Boat operator. No further action was taken that day.
  
  	I was contacted on Saturday May 21st, 2016 by the tow boat operator explaining that he was unable to raise the vessel Friday night and he was unsuccessful on Saturday morning as well. The tow boat operator contacted me Sunday afternoon, May 22nd, 2016 and advised me that the vessel had been raised and was being pulled out of the water at Keys Boat Works in Marathon, Fl. On Monday, May 23, I arrived at Keys Boat works and documented the sunk vessel with pictures.  
  
  I met with Operator1 and the marine surveyor contracted to assess the damage. Surveyor advised me that the probable cause of the sunk vessel was a equipment malfunction at the water line.
  
   Upon inspection of the after through hull amidships, you could see that something ran alongside the vessel freeboard at the water line and damaged the outside edge of the aft through hull allowing the hose and through hull inoperable. This hole allowed water to enter into the vessels machinery spaces while Operator1 was underway. 
  
  Operator1 did not have any high-water alarms installed on his vessel and so was not aware that his vessel had been taking on water while he was underway. Upon his change of direction astern, the vessel already swamped began to immediately sink at that position. 
  
  With the vessel out of the water, I also saw a large hole at the keel which also allowed water to enter into the forward berthing area. Upon further inspection, no striation marks were seen around the area which would conclude that the vessel incurred the damage post accident as a result of resting on the bottom and being subject to hard bottom and wave action.