You might find a way to communicate with Dr. Ballard by searching web sites dealing with
the Jason Project. The Jason Project is an online
learning forum developed primarily for elementary age kids and teachers to explore the worlds oceans
and follow Dr. Ballard's latest expeditions.
I can't say for sure but you might find an way to
email Dr. Ballard from that web sight.
However, Dr. Ballard is a very well known person.
I'm sure he's not able to respond to everyone that contacts him. So I wouldn't expect an immediate response.
Best of luck.
Hope this helps.