Thanks for all the astute comments and experience..I learned a lot. I myself dragged anchor in Key West on my 34'' O''Day sloop
setting a Danforth in the sandy bottom. I woke up at 2 am aground on a sandbar about 4 miles from where I had anchored. The boat dragged through a small flotilla of anchored boats and by the grace of God missed them all until coming to rest. Boat US Tow boat rescued me and got me back to a better anchorage. My problem was obviously not enough rode, a high tide, and strong current and winds. From then on I let out a lot my anchor line til the scope was at leat 6 or 7 no matter where I was in the Keys. No more dragging anchor I am pleased to report. The Danforth is great in the Chesapeake so far--with sufficient SCOPE.