At high enough speeds, such as 500 m/s, the simulation can break down in novel ways.
Sometimes, the SDV will stick in the water so long as the input is held and generate wake effects in all directions around the vehicle. The vehicle will only launch once the input is released. It has also stuck in the air before.
There is a video of the "air grab" here: http://www.youtube.com/watch?v=IArEpx8oieo