'In the event of encountering an underwater predator set on doing you harm, try to make yourself surprising, unpredictable an unappealing. If you are unable to do this, try hitting the predator on the nose. It's sometimes enough to dissuade from from attacking. Barring this, remove the pressure regulator from your valve. This will cause some mild discomfort as you emulate one of the ocean's own in a display that's sure to frighten away any predator. If this still does not work, then we apologize for looking tremendously silly when you meet an untimely end.'
-From the worn label of a mangled rebreather that washed ashore