Final answer:
The author aims to depict the calm and routine life aboard a peacetime ship, contrasting it with the potential upheaval that may follow, and to humanize the sailors by sharing their mundane experiences and observations.
Step-by-step explanation:
The author's purpose for writing the passage about sailors documenting routine operations such as the delivery of milk and ice cream is likely to highlight the normality and tranquility of daily life aboard a ship during peacetime, providing a stark contrast to the tension and chaos that can occur during conflict or emergency situations. This mundane documentation serves to humanize the sailors, giving readers a glimpse into their everyday experiences and the calm before a potential storm. By including a crew member's recollection of the weather, the author further emphasizes the peace and beauty of the moment, possibly foreshadowing a subsequent disruption of this serenity.