Thereafter, DELAG used the Graf Zeppelin on regularly scheduled passenger flights across the North Atlantic, from Frankfurt-am-Main to Lakehurst. In the summer of 1931, a South Atlantic route was introduced, traveling from Frankfurt and Friedrichshafen to Recife and Rio de Janeiro. Between 1931 and 1937 the Graf Zeppelin crossed the South Atlantic 136 times. The trips took about four days in each direction, and a one-way ticket was about $400, which translates to about $7,050 in today’s money.