In August 2014, Fortress Anchors conducted scientific anchor testing in the Chesapeake, utilizing the 81-foot research vessel Rachel Carson owned by the University of Maryland Center for Environmental Science. Testing was observed by Chuck Hawley, the former Vice President of Product Testing at West Marine, and Robert Taylor, a U.S. Navy anchor design and soil mechanics expert for over 45 years, consulted on the project. The bottom condition was soft mud, which is common in the Chesapeake Bay.
I have long argued that a lot of anchor testing is done in unusual bottom conditions that create odd results, whereas mud is the predominant bottom found in most harbors all around the world. Yes, there are extremely rocky bottoms in Chile, and some people never anchor outside of the sandy Bahamas or the coral-strewn waters of the South Pacific, but still the majority of harbors found up and down the coasts of North America and Europe are mud, which goes for most of the rest of the world, too.
Test results here.