Here’s an image of Ben Franklin’s map of the Gulf Stream, the ocean current Matthew Fontaine Maury famously called “a river in the ocean.”
It moves roughly 500 times as much water as the Amazon, and when it cools in the North Sea, its sinking brings nutrient-rich colder water up to the surface. (The Gulf Stream’s waters, like most tropical waters, are nutrient-poor and therefore clear.)
I’m reading an interesting book of popular science right now, The Gulf Stream by Stan Ulanski of JMU. Eventually I’ll write an article on the cultural poetics of this ocean current and its massive impact on early modern relations between Europe, Africa, and the Americas. More later.