The main image is a good depiction, from forward of the port beam, of the steam-driven submarine 'K10' under way. This was built by Vickers at Barrow, was launched on 27 December 1916 and broken up from November 1921. The bow shape is not quite accurate in that it did not curve downwards at the stem. The vessel among the sketches at the top is a steam drifter with its steadying sail set and possibly being used for observation if the torpedo bombing that appears to be in progress from the three aircraft is an exercise, as seems likely ( they are certainly not attacking the drifter). The biplanes involved are land-based aircraft of indeterminate type.