Fly in water should be automatic?

I'm pretty new to SL, so please take this suggestion with an appropriately sized grain of salt.

I walked off a bridge into the water once, and I fell all the way to the bottom. My avatar then did the "I fell off something tall" animation, which doesn't make much physical sense (yes, I know the technical reasons behind it --- but it still doesn't make physical sense).

Would it make sense to automatically turn on "flying" mode when falling into the water? Ideally, avatars should have some sort of bouancy factor based on body and attachments, but in the meantime, turning on flying mode would be an improvement over "water is just like air except darker and below the 'surface.'"

That would break every underwater home in existence

Not saying that you can't turn off the flying mode underwater... just that it should turn on automatically.