From
http://www.mercyhurst.edu/news/press_release/detail.php?id=1260 In one of the more dramatic moments of an underwater archaeological survey co-led by Mercyhurst College archaeologist James Adovasio along Florida’s Gulf Coast this summer, Andy Hemmings stood on an inundated river’s edge where man hasn't set foot in more than 13,000 years.
Donning full scuba gear, Hemmings stood in 130 feet of water on a peninsula at the intersection of two ancient rivers nearly 100 miles offshore from Tampa. The last time humans could have stood in that spot, mammoth and mastodon roamed the terrain.