Re dating of the top photo in Scotchie's #70, reproduced below.
The two vessels at the top of the photo look like Hunt class minesweepers, which entered service in 1917. They were a successful design some of which remained in service into WW2.
The vessel off the end of the Promenade Pier is a P-boat. These were a class of cheap 'n' cheerful patrol boats built rapidly under the Emergency War Programme and entering service from 1916 onwards, most being sold for breaking up in the early 1920's. They were mainly designed for anti-submarine duties and had a very low freeboard and cut down profile to make them resemble submarines and enable them to get to close quarters with a U-boat before being recognised.
The vessel on the slipway in the Wellington Dock is a drifter. These were used in large numbers in the Dover Patrol to tend the vast net and mine barrages in the Dover Strait.
Photo was therefore probably taken in 1917 or 1918 or possibly early post war.
This is one of the P-boats tied up to the mooring buoys in the outer harbour. She is HMS P57 which sank one of the coastal minelaying U-boats, UC47, in 1917. She was later sold to Egypt and renamed Raqib.