Jessen, Professor Otto
Otto Jessen (1891-1951) of Tubingen in Germany was another of a number of German academics, such as Schulten & Hennig, who, in the early part of the 20th century, were convinced that the answer to the Atlantis mystery lay in Southern Spain. Professor Jessen excavated at the mouth of the Guadalquivir River in Spain in a quest for Tartessos, which he believed to be Atlantis [413].
In the early 1920s he carried out studies at the Strait of Gibraltar, the results of which were published in 1927 [1564].
Atlantisforschung.de gives a good overview of his life and work(a).
(a) https://atlantisforschung.de/index.php?title=Otto_Jessen