Arden is having breakfast on the "All Alone" with Packy before he sets sail. As the ship is set to sail, rather than disembark, she remains on board to accompany Packy on his journey. Despite leaving for months with only the clothes she was wearing, she displays an extensive wardrobe while on board, all of which are perfectly tailored to her figure and style.
When Packy's girlfriend asks to accompany him on his South Seas boat trip, Packy says he sails alone. However, "alone" means with a captain, a captain's assistant, a cook, and a 5-piece band (at a minimum).