Here are three more covers for The Frogmen.
This 1950s edition is signed "Dix" but I haven't been able to find out anything about them.
Leslie Wood (1920-1994), who painted this Quality Book Club cover, was a Cheshire-based artist best known for their work on the Little Red Engine series. He also produced covers for Hugh Walters' science-fiction novels.
This revised Pan paperback edition dates from 1970.