Also, what was happening in Germany at this time? He sailed aboard the SS Berlin and was originally from Germany - he was on a return visit to see some family.
I never met him, as he died before I was born, so I can't ask him to explain what it was like back then. However, I was wondering if the fine historians of this subreddit can give me an idea!
In the summer of 1931, Germany was in much the same position that Greece is in today. In July, there was a big international conference ongoing in London to determine whether Germany would be extended a multimillion-dollar loan to keep its banking system and government afloat, and if so, how much.
One of my favorite things to do whenever someone asks a general question involving what the world thought or what the general reaction was to a specific topic, I like to go back to old newspapers. The New York Times has a wonderful feature called the TimesMachine that lets you page through back issues and search for stories. Here's the issue for July 23, 1931.
I'm not sure if you need to be a subscriber to use it, but if you aren't, I do encourage you to sign up. It's fairly cheap, and it's supporting a good cause.