2) Moonlight, 0.2 lumens, enough light with night-adjusted eyes to do most anything you need ~300-500 hours from a single AA. OK, except for the worst apocalyptic scenario, no one is ever going to need to run a single batt. 300 hours on moonlight. However, how much battery capacity do you think you will have when the SHTF - 50% on average? Then, how much additional capacity do you think you'll burn because moonlight may not be quite enough - 25% maybe? So if you've got 25% left to use where moonlight is enough, that 75 hours+ of light... what's that worth?
If you are stuck on a cruise ship for 300 hours, you've got other things to worry about than having moonlight mode. That's 12.5 days. I'd say after a few days you are fish food anyhow.