To sweep an anchor:
If you have lost your anchor, and there is chain or hawser on it, you can recover it by dragging with a grapnel back and forth across where you suppose the hawser is lying. If there is no chain or hawser attached, you will have to sweep for it. Take two boats and pass a weighted line between them, then row back and forth, dragging the bight of the line across the bottom until it finds the lost hook. Sometimes you can get an anchor by making fast one end of the sweep and rowing round in a circle, paying out the line as you go. Let it sink; then bring both ends together, as fishermen do a net, and haul in slowly. The best sweep is one made with a piece of chain in the middle.