I see, Alan. Then another way would be to place the chain at a hyperfocal distance of what looks like about 4 meters in the first image and focus on it with a slight loss of detail at the dockside.
Indeed, looking at the first image, it happens that your f/6.4 and 24 mm focal length gives a hyperfocal distance of 4.7 meters so, if the chain is to be a feature of the shot, then setting the focus distance to say 5 meters in manual mode would be about right, with little or no loss of detail at the dockside.
While some photographers can't function without focusing on something in AF mode, sometimes benefits can accrue from using MF like "real photographers" used to do all the time.