But these sailors aren’t working 24/7 non-stop. Individuals have downtime to sleep, eat (obviously), and generally hang around playing video games, watching movies, reading, etc (this one is not so obvious). They would’ve had to bring an that stuff onboard before they left.

I mean they are at sea and doing the 24 hour work rotations, its not 8 hours of work with 16 hours off. Not sure about us vessels but other navy’s I know of have multiple watches and while at sea your getting rotated though all hours. Its just not something you can expect from someone for these periods of time.