On a side note, how long to zombies stay animated? Does it take days, weeks, or months for the brain and muscle tissue of an animated corpse to decay to a point that it is unable to function? Or is there a function of the zombie virus that preserves it’s host longer than is natural?
Assuming that 85 to 90% of the world’s population succumbs to the plague in a relatively rapid fashion I assume the 10 to 15% of survivors would be able to find secluded refuge and wait out the zombie apocalypse.
If faced with survival in a zombie apocalypse scenario. I would collect as many supplies as possible and hijack a tanker ship and stay at sea for months until the dead stop walking. Just saying.
Bodies decompose is pretty fast, so probably a month, maybe two. Unless it's magical, in which case throw science out the window.
the survivor rate could be as much as 30-40% depending weather and reporting. In fact, even if it were possible, I don't think a zed outbreak would get much farther than a few miles from its place of origin (read city or town) unless someone was actively causing the outbreaks like terrorist. It is quit likely that the resident evil protocol of nuking an infected area would happen before the virus spread could else where (and I am adding in the bureaucrats).
It would probably be smartest to pick a smaller boat, less likely to pick up unwanted zed passengers. what you want to do is go island hopping to seek out other survivors, chances are that plague won't make it to the island outposts before you do and it really isn't wise to take a tanker ship without a crew unless you want sit in the harbor while the forces of undeath surround you and the city burns.