Full title reads: "Home Guard Navy".
MS & GVs of a meeting of amateur boatmen who are volunteering for home defence duties with their boats. This group of the LDV (Local Defence Volunteers) are inspected by Sir Basil Brooke (paperwork suggests they are the Home Navy Thames Defence Force).
VS of little boats, river cruisers and motorboats moving along the river in formation. The two or three men who crew each ship are lined up on the decks.