SEATTLE — When Jeff Bezos and his former wife, MacKenzie, celebrated what would be their last anniversary together around Labor Day 2018, they arrived at a Miami nightclub with no fanfare. His table was booked online, which is “totally what tourists do” and “totally dorky,” the club’s celebrity liaison said in an interview at the time.

Almost a year later, Mr. Bezos arrived at a hot Miami seafood restaurant in grander fashion, on a 90-foot-long Leopard superyacht in what The Miami Herald called “the most extravagant entrance ever.”

It was not his only superyacht of the summer. He lounged with his girlfriend on the media mogul David Geffen’s boat in the Mediterranean, along with the supermodel Karlie Kloss and the former Goldman Sachs chief executive Lloyd Blankfein. Mr. Bezos, 56, was also spotted on a ship owned by Diane von Furstenberg and Barry Diller off the coast of Venice. After gossip sites gushed about the $260 purple octopus swim trunks he wore in many photographs, the swimwear quickly sold out.