HISTORY OF FLIGHTOn August 18, 2019, about 1330 central daylight time, a Cessna 206 float-equipped airplane, N5364Q, was destroyed when it was involved in an accident offshore of Hopedale, Louisiana. The commercial pilot sustained fatal injuries and 2 passengers sustained serious injuries. The flight was conducted under the provisions of Title 14 Code of Federal Regulations Part 91 as part of a fishing lodge package. On the morning of the accident, the airplane departed from Barataria, Louisiana, about 0600, for a fishing location in the northern part of Chandeluer Sound. The fishing location was located about 29.946505 N -88.845796 W. There was another float airplane from Barataria (N7896S) at the same location. After a morning of fishing, the pilots of both airplanes started to prepare for a return to Barataria. According to the pilot of N7896S, the weather was starting to deteriorate with heavy rain. Both pilots waited about 45 minutes to an hour for the weather to get better. After seeing a break in the weather, the accident airplane (N5364Q) took off about 1300, heading about 240-degrees. N7896S followed about 2-miles behind and was in radio contact with the pilot of N5364Q. The pilot of N7896S encountered heavy rain and lost sight of N5364Q, and lost radio contact with the pilot of N5364Q. Upon returning to Barataria, the pilot of N7896S contacted authorities and a search began for N5364Q. The Coast Guard searched the area and found the pilot and 2 passengers of N5364Q. The pilot did not survive, and the 2 passengers were transported to a hospital. METEOROLOGICAL INFORMATIONWeather data showed a thunderstorm cell in the immediate vicinity of the approximate accident site at 1330. The estimated flight path of the accident airplane was within a few miles of the thunderstorm cell. Satellite weather images showed cloud cover over the flight path and accident area. Both surviving passengers stated that the airplane was flying beneath low clouds before it impacted the water. WRECKAGE AND IMPACT INFORMATIONSevere weather for several days after the accident precluded immediate location and recovery of the airplane wreckage. After the weather cleared, a 4-day sonar search for the airplane wreckage was conducted encompassing 82 square miles around the accident area. Only portions of the airplane wreckage were recovered, and the engine was not found. The available wreckage was examined, and no anomalies were found other than severe water impact damage. MEDICAL AND PATHOLOGICAL INFORMATIONAn autopsy on the pilot was performed by the New Orleans Forensic Center, St. Bernard Parish. The cause of death was drowning. Toxicology testing was performed by the Federal Aviation Administration Bioaeronautical Research Lab, Oklahoma, City, Oklahoma. The tests were negative for alcohol. A small amount of Naproxen, a pain medication, was detected.