Willy Hanke Biography
posters by this artist:

NDL Bremen Lloyd Frachtdienste, 1935
Norddeutscher Lloyd Bremen ins Mittelmeer, 1930

known designs include:
Bathing suits -- 1920-1940.
Beaches -- Germany -- Norderney -- 1920-1940.
Cabanas -- Germany -- Norderney -- 1920-1940.
Travel -- 1920-1940.
Norderney (Germany) -- 1920-1940.

Library of Congress reference:  http://www.loc.gov/pictures/item/2008680350/