Many large ships use long amounts of heavy chain and relitatively small anchors--where the chain gives friction. Generally small (less than 60 feet) cruising boats carry 200 feet of chain and back up rode in nylon to give a total of at least 500 feet. We always use 7:1 on both bow and stern when possiable. In 100 feet of water (very unusual) all of the chain is on the bottom--in the average anchorage of 20 to 30 feet this equates to abour 200 feet to give the 7: 1 scope. Generally the second bower has 25 to 50 feet of chain and the stern anchors in the 25 to 35 feet of chain and the rest rope. Bob Austin