How much of human history is on the bottom of the ocean

Sunken relics,ghostly shipwrecks and lots of cities are on the bottom of all the seas around the world.Some from the biggest and interesting things were lost years ago. These things are from every country and they say how was life in the ancient past was.If they were in our museums,people would go to museums and enjoy these fantastic things which people made many years ago.I recommend watching this interesting video and the other videos from this site.The link is below.

http://ed.ted.com/lessons/how-much-of-human-history-is-on-the-bottom-of-the-ocean-peter-campbell