Well as interesting and as facinating as it is for a lot of us I would say it doesnt even come close as going to the moon. Going to the moon was part of a much larger space program. The things that came of out the space program that were huge contributing factors to the developement of techonlogy that we all use and enjoy today dwarf anything that the discovery of a shipwreck ever did.
They both have their challenges but getting into and beyond orbit is way more difficult. The energy differences alone are not even comparable among many others to overcome. Don't get me wrong. Submersing in a steel bubble especially to great depths is no easy feat and can be very dangerous and the developement of that technology has contributed also. But the impact on everyones daily lives of things we use and enjoy today from the space program is huge.