Wood Sandpiper; Andarríos Bastardo

My first thought was Common Sandpiper but they stay on the margins while these are a long way out from the edge. I watched for half an hour and both birds stayed well out in the water. There were also Common Sandpipers present, the white wing bars were obvious when they were flying. These never flew and also the darkness on the breast extends towards the legs without the distinctive cut off of the Common Sandpiper.