The financial support of the Lübeck physician and local researcher Rudolf Struck (Gatermann illustrated Struck's books The Old Civic Residence in Lübeck, Volumes I and II) enabled him to study in Munich's Academy of Fine Arts.
In the summer of 1922, he accompanied Rudolf von Laban and his dance group, creating an expressive cycle of movement studies.
In Berlin in 1923 and 1925, he exhibited his watercolors in the galleries of Rudolf Wiltschek and the Kunsthaus Heumann in Hamburg in 1926.
In 1928, he became acquainted with the painters Otto Niemeyer-Holstein, Ernst Frick, Albert Kohler and the writer Werner von der Schulenburg.
Gatermann predominantly focused on north German landscapes and cities, though he also painted still life and figurative scenes, and portraits of people including Marie Curie, Wilhelm Furtwangler, Otto Bernheimer, Julius Eugen Kopsch, Hans-Peter Mainzberg, and Otto Anthes.