Thomas Mann makes heavy use of repetition to illustrate his characters in this novel. This page will be expanded with more characters and characteristics (some characters have multiple "trademarks") All quotes and page numbers are from the John E. Woods translation, Everyman's Library edition.
When Director Behrens walks it is sometimes described as "rowing" to emphasize the enormousness of his hands (i.e. they are like oars)
...there were the two doctors striding across the open area at the back of the sanatorium — the director in his white smock leading the way, his head thrust forward, his hands rowing in the air...
— page 73
And behind the doors where these potbellied container stood lay the dying or the moribundi , as Director Behrens called them one day, when Hans Castorp chanced to meet him on the second floor — just as the purple-cheeked director in his white smock came rowing down the corridor.
— page 124
And with knees slightly bent and rowing with his hands, he began to trudge downhill, a trail of cigar smoke billowing behind him.
— page 207
...Tienappel learned from tall, colorful Director Behrens — who came rowing through the dining hall, gliding about, his black and pale assistant in his wake...
— page 514
Notice the additional nautical detail of giving Behrens a "wake"
The director, his neck arched, was just rowing off toward home...
— page 626
His head tilted toward one shoulder, he watched the director row away.
— page 747