Rick Kasten is a ship's owner.
Not too many from that profession get involved in the espionage game; it is horribly bad for business. Kasten would not have done so himself except for his immense dislike of the Nazi regime and their treatment of the Jews. Which is why in the two-book series we have of this man's adventures we follow him first doing what he can to save who he can and then later taking his involvement in the "spy game" a huge leap forward.
When first we meed Kasten, he is in Havana, Cuba, quite a ways from the new war just about to erupt in Europe in 1939. Kasten is described as "single, reasonably fit, and tanned from days in the sun. Although on the short side of forty, he was starting to show some gray at the temples."
I started to call Kasten the captain because of his control of his vessel's operations but that is incorrect. He is really the ship captain's boss, the CEO of Guarana Steamship Lines, a successful shipping enterprise in the North-South America trading world. Grandson of the founder and trained from a young boyhood to eventually take the reins, he became the chief negotiator and business wrangler for the firm after the passing of the older gentleman.
One of the fairly lucrative business deals that Kasten got for his company was the transatlantic run to a German company delivering fruit, coffee, and tobacco from Cuba. The return trips, though, were how his presence in this collection came about because he would, operating mostly in a legitimate manner, haul in his now empty vessel back to the Americas refugees who were "willing to pay for passage and the Reich's price to exit".
It sounds straight-forward and simple. It does not stay that way.