HISTORY OF FLIGHTOn May 6, 2022, at 0844 eastern daylight time, a Cirrus Design Corp SR22, N24LA, was substantially damaged when it was involved in an accident in the Atlantic Ocean near Tybee Island, Georgia. The private pilot was fatally injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. A review of automatic dependent surveillance-broadcast (ADS-B) data and air traffic control information obtained from the Federal Aviation Administration revealed that the airplane departed runway 27 at Whiteplains Airport (SC99), Lexington, South Carolina, about 0738. The airplane turned to a southbound heading, climbed to an altitude of about 4,000 ft mean sea level (msl) and flew for about 10 nautical miles (nm). The pilot had requested and was given an approach clearance for the RNAV GPS approach to runway 17 at Barnwell Regional Airport (BNL), Barnwell, South Carolina, about 48 miles from SC99. The air traffic controller requested that the pilot provide a position report inbound on the approach over the “FATSU” waypoint. The pilot acknowledged the request but did not report passing the waypoint. The airplane overflew runway 17 at BNL at about 2,200 ft msl and continued to fly another 113 miles on a 170° heading. The airplane crossed over the eastern coastline of Tybee Island and continued over the Atlantic Ocean for about 15 miles then began to slow and descend briefly. Then, when passing through about 1,500 ft msl, the airplane entered a left arcing descending turn with a corresponding increase in groundspeed. The last ADS-B data received was at 0844, as the airplane descended through 75 ft msl about 18 nm southeast of Tybee Island. ATC asked pilots in another airplane to check on N24LA. The pilots rocked their wings but were unable to get the accident pilot’s attention and they continued to watch as the airplane descended into the ocean. WRECKAGE AND IMPACT INFORMATIONPostaccident examination of the recovered airframe verified flight control continuity throughout the airframe from the cockpit controls to all primary flight control surfaces. Examination of the airframe and engine revealed no evidence of mechanical malfunctions or failures that would have precluded normal operation. MEDICAL AND PATHOLOGICAL INFORMATIONAn autopsy of the pilot was performed by the Division of Forensic Sciences, Georgia Bureau of Investigation, Coastal Regional Medical Examiner’s Office, Pooler, Georgia. The cause of death was “drowning”, and the manner of death was accidental. Toxicological testing performed by the Federal Aviation Administration’s (FAA) Forensic Sciences Laboratory detected ethanol in the pilot’s heart blood tissues. Metoprolol was detected in his heart and liver tissues; this high blood pressure medication is generally considered non-impairing. Postmortem ethanol concentrations in blood samples have been positively correlated with the number of days before body recovery at sea. The pilot reported a history of ablation for atrial fibrillation with a loop recorder implanted, for which he had received an FAA authorization for special issuance. During the time that the pilot did not report the waypoint and did not respond to ATC, there was a 7:43 minute period of tachycardia with a median heart rate of 300 beats per minute.