Thames swan masters checking up on swans - this is called swan upping.
Full title reads: "WINDSOR".
Various shots of the Thames swan masters organising and marking swans around the river. Men are seen rowing in their small boats, looking for swans. Their duty is to count and mark the swans as well as to distribute them evenly along the river so they have enough space and food. Several shots of the men handling swan. Several hots of the men releasing swans into water.