50/50 shot on weather. It's hurricane season & several people I know that took this cruise (assuming you are going out of NY area?) loved it, however, if there's any sort of hurricane sitting wayyyyyyyyyyyyy down in the Caribbean & no chance of striking you - you will feel the waves.
Because the hurricanes push basically north, the waves that run ahead of it can be felt as far up as Bermuda. One of my friends that did a cruise to Bermuda had her trip cut a day short because the ship left for NY a day earlier than planned when a hurricane decided to head north. They basically had to out run the hurricane, but she said they had 15 foot waves on the way home & the hurricane was still way down in the West Indies area, that's at least what? 500-700 miles away?
The Zenith is a small ship as well, not as big as the other ships, so you will feel the ocean a bit more vs. sailing around the Caribbean.