Chances are that as you're reading this, you are somewhere within the scope of a land mass on earth. That's because, if you're reading this, chances are also that you're a human person, who breathes air and gets around either on foot or on wheels. There's a possibility that you're in a boat or a plane over a body of water, and a smaller possibility that you're in a submarine vehicle, or that we have readers in a subaquatic Atlantis -- and if that's the case, you should know that you're still unknown to terrestrial cartography and we'd love for you to get in touch.
But in all likelihood, you are within the land border of some country or territory, because human beings are by necessity attached to the ground beneath our feet. We need somewhere. Even somewhere we don't want to be. Someplace to sit or stand, rather than sinking or swimming (no offense meant to any Atlantian readers), or else float off into space.
The majority of our world is covered in water; that's a mindblowing concept if you think of how much world there already is if you're only considering the land. There are places at the bottoms of oceans that haven't been fully mapped, that are too dark and dangerous for us to even know what is there. The wildness of the surface and the mystery of the depths are a formidable wonder to humanity, comparable in a certain way to our relationship with outer space. But where the mystery of space is its apparent infinitude, the mystery of the sea is obscurity despite measurability and proximity. It's right here, but we can't comprehend its volume, and it represents another 'final frontier' on our own marvelous planet. Bodies of water of any size and depth inherently represent a boundary for us, because we can't cross them without special equipment. Even the shallowest stream requires a change of shoes.
When a lake or ocean appears on a map, it is normally depicted as a totally flat plane, with its name floating across, and its edges clearly defined. It is a lovely blue off-limits zone, its edges both a boundary and a destination, because human life happens on land but needs the water. What's interesting is that the area occupied by water, although exactly as real as the world on land, is categorically reduced to a planar existence because that's what makes sense with regard to above ground life and navigation. Any more complex information about currents, bathymetry, marine biology, the dangers and wonders that are happening in a given body of water, is only available through further research and special tools to people who intentionally go out there for work or leisure.
Of course, there's nothing wrong with the way cartography normally treats maps, since the content of the land is normally a much larger part of the map's intent. Showing bathymetry or information about currents might throw the map off topic, and if you're just trying to get to the next town, you only need to know where the water is, and how to get over or around it. We prefer to leave out the information we don't need as much, so we can show more of what we do need. But it's interesting to think that our inability to inhabit water leads us to think of it and depict it so simply.
How would mapping be different if the human body were amphibious, and if we could live just as easily underwater as we do on land? If we could breathe underwater indefinitely, could swim as easily as a dolphin, eat what's down there, drink salt water, and see with limited light -- even if we could only live underwater up to a certain depth, just like we have altitude limits, that would totally reshape our occupation of the planet. For one thing, maps wouldn't show bodies of water as flat blue planes, because it would matter what's under the surface, and we'd have towns and cities under there that you might want to travel to. It would be more important that the features of the world under the water were depicted with accuracy, than that the edges are accurately defined. How fascinating would it be to see a map produced by an underwater cartographer, whose family has been living in the Gulf of Mexico, or Lake Erie, or the Mediterranean, for generations! Which information about the land do they leave out, to make more room for details about their subaquatic home? Up here we have trees and plants we make into paper, and we draw maps on them; what do they have down there? Sand? Maybe they make glass maps out of sand and engrave the information with a clam shell. There's a special study of sea maps where you can learn to tell where it was made by the minerals in the glass. More ancient ones were made of thick ropes fiber and seaweed, and could be several inches thick, but they disintegrated over time and now they prefer to use glass.
If people could inhabit the water as easily as the land, exploration of the world would probably have looked very different. And we'd likely still gravitate toward the coasts and the rivers because we still need water, but now it's also because you want to be close enough to visit your aunt and uncle a few miles offshore. There would be cities half-in and half-out of water, floating cities you climb up on out of the sea to spend the weekend in the sun. Seasonal migrations to get away from inland droughts or offshore hurricanes. Strong opposing viewpoints on which environment people truly belong in, and on whether the whales are our friends or our food. We use the currents as a natural highway. Underwater weathermen develop advanced strategies to warn the people on land about storm events. How different would political boundaries look, and our relationship with the environment? Dumping trash in the ocean would be like an act of war. Maybe the bluefin tuna would still be endangered, or maybe we would farm fish like cows on a massive scale, and find ways to avoid overfishing.
It would be essentially a different planet for us if we were able to navigate the planet differently. Whether we were naturally amphibious or we got there through technological advancement, it would fundamentally change our experience of the world and our relationships with the environment, and which details about our surrounding we consider most important. So we would draw it differently.
Cartography is different from photography of the earth because it involves the infusion of human understanding into our depiction of the world. At this stage in history, we have no lack of high-resolution satellite imagery of the planet, but we rarely refer to that as a map. Why? Because regardless of the medium or manner of production, cartography is a scientific art of representing places. Unlike many kinds of art, there are wrong and right and better ways to do it -- just like in architecture. To make a map is to process information about the world through the lens of human understanding, for the purpose of human understanding. We can hardly understand anything from satellite imagery alone. So we label it with language, and draw over it with lines, grids, numbers, and symbols, we specialize it so we know what we're looking at. Now it's becoming a map. We might replace the satellite imagery because despite its high quality and realism, it often makes a pretty crappy basemap, especially if you'd rather have, say, the terrain represented by contour lines, you want to see the architecture, or you're showing demographic information with colors and tones. Realism doesn't always tell us the most about reality.
To make a map is to simultaneously make information more accessible, and more specific, less universal. I can't read a map written with Chinese or Arabic characters, for example, and there's any number of approaches to symbology that I won't be familiar with without an explanation, in my native language. I do that to other people every time I make a map. And of course we want to make maps that will be as nearly universally understood as possible, but this limitation, the need for interpretation, is inherent to the cartographic process of filtering information about the world for human understanding. We select and specialize the information because no map can ever legibly present every attribute of a place, past and present.
The cartographer has to include what's relevant for the purpose of the map they're assembling. By departing from photorealism and lists of raw information, processing what we know, and leaving out certain things like what's under the surface of the water, we gain a distinctly human portrayal. One of literally infinite possible portrayals from billions of perspectives. The strength and purpose of the map as a work of art and as a tool comes from the selection of data: what we leave out, and what we layer in because it seems important. A person's perspective is theirs because it is limited; that's where art comes from.