On 05/09/2023 at 0908 hours, Florida Fish and Wildlife Commission (FWC) was conducting routine water patrol in a marked FWC vessel. 
At 1:09 PM I observed a radio transmission stating that a vessel was taking on water approximately 2 miles west of Key West. I informed FWC dispatch that I was enroute to the vessel. As I moved to the reported location I was informed by FWC dispatch that the U.S. Coast Guard (USCG) had arrived on scene. I raised USCG on the VHF radio and was infomred that all persons had been removed from the vessel and that the vessel would be towed to Robbie's Boat Yard in Key West.
At 1:09 PM I observed a radio transmission stating that a vessel was taking on water approximately 2 miles west of Key West. I informed FWC dispatch that I was enroute to the vessel. As I moved to the reported location I was informed by FWC dispatch that the U.S. Coast Guard (USCG) had arrived on scene. I raised USCG on the VHF radio and was informed that all persons had been removed from the vessel and that the vessel would be towed to Robbie's Boat Yard in Key West.
I identified the vessel owner/operator as OP1. A second owner was identified as a passanger on the vessel.
I identified the vessel as a 1985 Carver brand cabin motorboat, white in color. 
I spoke with OP1 and arranged to meet him at the vessel on 05/20/2023. I obtained a written statement from OP1. In his statement OP1 stated that he was operating his vessel in Atlantic Waters approximately 2 miles off Key West. OP1 stated that he was traveling a route that he has used many times in the past. OP1 stated that his chart plotter was not functioning but based on his position adjacent to marked channel he believed that he was in 12 feet of water as he traversed the reef line. OP1 stated that his vessel struck a submerged object and in doing so began to take on water. OP1 stated that smoke began to come from the engine compartment. OP1 stated that when PAX 1 observed the smoke she called the U.S. Coast Guard. OP1 stated that USCG arrived on scene followed by SeaTow. OP1 stated that he instructed SeaTow to take his vessel to Robbie's Boat Yard on Stock Island.
I obtained digital images of the vessel. I inspected the hull of the vessel for damage. Based on my observations I determine that the vessel struck a submerged object. I determined that the vessel did not come aground as the limited amount of damage does not support a grounding. I observed the port rudder to be bent toward the stern consistent with striking an object. I observed no hull damage.
I conclude that the accident was a result of several factors. The first factor was equipment failure as the vessel did not have an operational chart plotter. The second factor was operator error as OP1 believed that he was in 12 feet of water when, based on the draft of his vessel, he was operating in less than 5 feet of water.

Atlantic
MARATHON                      