With all due respects to the Titanic researchers, I found it amazing that bones remain from shipwrecks dating hundreds of years before the Great Ship went down. Maybe some have been seen, but to protect the dignity of the victims, they have not been made public. Yes, many pair of shoes and boots lie side by side, but I find it amazing that absolutely no recognizeable remains have been spotted.
Bodies on the floor of the Great Lakes are very well preserved, where there is no oxygen. And I'm sure there's very little O2 at 12,500 feet below the North Atlantic.