I need a dream interpretation?

I've been having this dream since I was a young girl, and it keeps reoccurring. The dream is of me, in a DEEP, murky lake, in the middle of some kind of forest. There's a sunken car, and a bunch of crocodiles are swimming around. They don't seem to care too much for my presence. While wandering around, I noticed I somehow don't have a breathing problem. No matter what I do, I can't seem to swim up towards the surface. What can this dream mean? Thanks. :)