That's an interesting question, though I wonder if many such people would have survived the journey all the way across the ocean without access to fresh water o

That's an interesting question, though I wonder if many such people would have survived the journey all the way across the ocean without access to fresh water or an understanding (and the necessary materials) for desalinating seawater. Some may have, but there are lots of filters working against survival, of increasing efficiency the further back in time we look.