Unit 1 was traveling towards charleston harbor from the wando river. Once he and his 4 occupants neared the arthur ravenel bridge, Operator1 stated that he heard an explosion from the stern of his vessel on the starboard side and smoke began to appear. Smoke then came from the cabin. Operator1 stated that he began to see flames and advertised a mayday call over his vhf radio to the us coast guard. At this point, he stated that he activated his vessel halon fire extinguishing system that his vessel was equipped with, but the fire continued. The officer then asked if the vessel was equipped with pfd's and if he and his passengers used them. He stated that the vessel was adequately equipped with pfd's however, they were in the cabin and the cabin was full of smoke and they could not be reached safely. Due to the inaccessability of the pfd's in the cabin he and his passengers took hold of the fenders within reach and jumped into the water. He then stated that a recreational vessel came to assist all four individuals in the water including himself until the uscg arrived on scene. The uscg obtained the individuals and a charleston county fire and resue vessel arrived on the scene in attempts to put out the flames but the boat continued to burn and eventually sank at the gps coordinates provided via coast guard sector charleston to myself. The individuals were then escorted to charleston city marina.
The operator cannot give a known reason for the fire and the cause of the fire at this point it is unknown.
