Yes, navigable water has always been the crucible of trade. Hence the economy and culture of the Mediterranean even from the early bronze age. And coastal trade is compelling, you don't need sea-faring ships, just dinghies capable of sailing to the next beach. So we can, reasonably, argue that there was a global human economy and civilisation (albeit one that operated really slowly) as early as 5,000 BCE (date that Wikipedia quotes for earliest depiction of a sailboat).
