[Dan Day]

People NEVER need special communications devices while diving in scuba gear. Even if their ears are exposed to the water, they can speak and hear each other clearly.

I can top that one -- in "Superman II", the villains carry on a normal conversation while standing on the surface of the Moon, which is totally airless.

[RandallFlagg]

Oh, YEAH??

In "Fantastic Voyage", NOBODY'S scuba gear emits ANY bubbles!!

[RandallFlagg]

And....

Gigantic, murderous sharks can easily outrun anything:

Jaws 2- speedboats

Jaws 4- Airplane