I wouldn't want to be anywhere near a Bull Shark while scuba diving!
Not really. Scuba divers aren't on their menu. The joke among sharks is that the "hard bits" on a divers back make you fart.
The only time a diver is really vulnerable is while spearfishing (which I don't do), in really low viz (like a surf line), or (maybe) on the surface where a curious shark might take a nibble. The Bull Shark that I saw back in January disappeared almost as soon as he/she appeared.