When was the wreck of the Titanic finally discovered and by whom?

It was discovered in Sept 1, 1985 at 2 am by a new piece of video equipment called "Argo" which was being used by a US Naval research ship Knorr. I believe Robert Ballard led the expedition.

He led another one in 1986 and this time used used a deep diving submersible named "Alvin" which was capable of carrying 3 people.

Spot on Georgia