If there is a river current you could also use such an arrangement for drudging. Tie the anchor back onto the chain (ie fouled) so it cannot dig in, then just let it drag along the bottom. You will drift slowly down current - speed controlled by current & length of chain/rope deployed. The current will move faster than the boat giving enough flow over the rudder for good manouverability. Trick used by square riggers in rivers before the days of steam tugs or when owner was too tight to pay for tug! Could get you out of trouble some day.