If Homo erectus could harness fire, it is quite likely that they could figure out what makes things float and how to stabilize such a craft. Having said that, forty miles is a fair distance, especially since you can't see from here to there, even on a clear day. This is also the first evidence of any pre-modern technology of any kind on Crete.
Crete has been separated from the mainland for about five million years, so whoever made the tools must have traveled there by sea (a distance of at least 40 miles). That would upset the current view that human ancestors migrated to Europe from Africa by land alone.
"The results of the survey not only provide evidence of sea voyages in the Mediterranean tens of thousands of years earlier than we were aware of so far, but also change our understanding of early hominids' cognitive abilities," the ministry statement said.
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