What about the water that would get inside a small boat, kayak or canoe? Or crashing a plane in to the water, but only sinking if it has cracks and water gets inside.I mean ofc that's the plane job to react to the impact those physics are apart.If the plane doesn't get cracks from the crash = no sink.
Oh yeah... and like depending on the proportion of the water getting inside the "vehicle" ( boat / canoe / submarine / crashed plane / battleship or Titanic ).I know a part of the water special effects will be made out of particles.But if it can be made so we can calculate the mass of the water that gets inside to make things right and get the "vehicle" JUSTICE!... I mean... a boat turned upside down would be nice to float if it has 5% air under it... you know stuff like that.Giving the opportunity for more possibility.