Not everywhere can run the latest and greatest OS
From the hundred or so comments on here, it seems to me that most have been made by people who are familiar with the typical IT world, and not so familiar with the OT world.
The ship will indeed have XP and even Windows 2000 systems on it. Most of them will be running SCADA applications to control the a/c and the like. I know it's surprising, but many nuclear power plants have the same deal, as do major transport systems, or conventional power plants, or water treatment plants, or pharmaceutical plants or.... You get the picture.
Is it a problem? Yup. But, there are reasons for using those 'legacy' systems, mostly to do with being proven to work and having been validated. Upgrading to a newer or alternative OS and patching them (oh yes, the ship systems will most certainly not be getting patched like most offices, even those running current OS installations), just isn't easy - please bear in mind not every machine runs browsers and fancy text editors all day, and the outcome when the kit doesn't work is more "problematic".