Hello,
its a 1 cy Pectoral Sandpiper. Please note well demarcated streaked breast, contrasting sharply with white belly. Apart from that it looks like a 1 cy Dunlin and a 1 cy Ruff.
If you see a wader, and you cant decide if its a juvenile Dunlin or a Ruff and it has a unform dark patterned breast, its a Pectoral SP.
Good find, congratulations!