What happened
An airline transport pilot initiated a departure from a private airstrip during the night under reported marginal VFR conditions. Prior to the flight, the pilot did not obtain a weather briefing or file a flight plan.
Approximately 150 feet above the ground, shortly after takeoff, the aircraft entered instrument meteorological conditions consisting of fog and clouds. This resulted in the pilot losing visual contact with the terrain and becoming disoriented. The airplane subsequently struck trees before descending into the water. The impact caused substantial damage to the aircraft, which then sank.
The pilot and one passenger both escaped the wreckage with minor injuries. The pilot reported that no mechanical malfunctions had occurred during the flight.