No, it's the fight of two metals and aluminum will always be the victim. Salt water could be a catalyst but not the main reason behind the problem..
And after all, why would one dive with a bronze watch anyway? Nasty green rust spots will happen especially in between the lugs and other difficult to clean areas and in a few years the watch case will be full of small pits or even worse, covered in green rust like a relic from the Roman Empire.
Oy! ''Tis the watch of Julius Caesar ! LOL