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Please note that Diamond Princess does not have a 24-hour-a-day eatery outside of room service. All other Princess ships currently sailing Hawaii round-trip from the West Coast (Los Angeles/San Francisco/Vancouver) do.
I know this would not matter to most people, but I consider this because I am an extreme night owl*. When cruising -- especially when the itinerary includes many sea days -- I prefer a ship with at least one eatery available 24 hours a day outside of room service.
Pre-COVID, one thing NCL/RCL/Carnival/Princess had in common was: 24 hour a day eateries available outside of room service, on most of their ships in their fleet. Pre-COVID, the exceptions I am aware of were:
RCL's four Radiance-class and four Vision-class ships;
Princess' Diamond Princess and Island Princess (of the ships still in the fleet).
-- In these early post-COVID times, I know some Princess' International Cafes closed late night (some still not 24 hours yet), and Carnival has started closing all pizza eateries from 3am to 8am (hopefully just temporarily).
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* When not cruising I usually don't sleep until after 4 or 5 AM. On a ship I don't necessarily eat at 3 or 4 AM, but I enjoy having a place outside of my cabin [especially if my spouse is sleeping] where I can hang out at a table near others and drink coffee and read/plan/etc.
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