‘Mapping oceans gave humans knowledge — and the arrogance to claim seas as territory’

You’ve authored ‘Tracks on the Ocean: A History of Trailblazing, Maps and Maritime Travel’ — how were markings visualised on ‘boundless seas’?
■ The idea of leaving tracks on the world as we move is not an intuitive one. We do so on land if we’re on a surface where our footprints remain but on water, it’s a strange idea. This began entering usage to understand navigation on water surfaces which are simply huge. The growth of oceanic navigation was important in the development of the idea of ‘tracks’. Obviously, it’s a fiction as you’re still not leaving a line on the sea but it became a tool to understand where you’re going, where you’ve been — and what you claim to have seen and occupied. A ‘track’ could turn the sea into territory.

What were some turning points in sea-mapping?
■ A crucial moment came in the early 16th century. A Spanish expedition, led by a Portuguese navigator, Ferdinand Magellan, went out in 1519. Magellan perished but a few survivors did return to Spain in 1522 — this was the first recorded circumnavigation of the world. Quite soon, you start seeing the first maps that show a voyage as a line in European texts. They’re globes or planispheres the 1520s onwards — and this was just when Europeans started transoceanic navigation. They went onto the Atlantic, the Pacific and the Indian Ocean. In the 18th century, there was an intensification of charting the Pacific Ocean. James Cook was a famed navigator attempting such colonial venturing.

Which discoveries helped such charting?
■ The development of techniques for pinpointing latitude and longitude really helped cartographical culture. Importantly, a lot of local knowledge also got drawn into maps. Captain Cook, for instance, interacted with Tupaia, an indigenous priest when in the Pacific. Tupaia drew a map for him. There was collaboration there. So, European navigators weren’t just going out with their tools and measuring — they were also relying on local knowledge, embedded into charting. The chart codified this knowledge — this reflects how what someone might have called their ‘discovery’ was often something someone else had long known.

Was there a link between the Western mapping of oceans — and slavery and colonialism?
■ For slavery, the main link was this huge maritime dimension — thousands of ships were crossing the Atlantic in the horrible trade in living people. Similarly, there is a link with colonialism because consider the earlier voyages and Magellan — what were they doing? They were going out to find new riches on the other side of the world, so the impulse behind some of this original exploration was certainly colonial.

Creating accurate charts allows you to visualise the world and stake claim to it. In the 17th century, European jurists were discussing whether the sea was free or if, like land, you could draw boundaries and claim chunks of it. Mapping was central therein — it directly underlies the laying of colonial claims.
How did maritime mapping shape humanity’s view of the environment?
■ A map is reassuring because it’s literally a plan — you know where you’re going, you know other people have been there and you know what the place holds. A map facilitates travel because it makes the world more graspable. You have it on your little round globe or a flat piece of paper. With printing, more people got used to imagining the world through modern maps. That truly changed ideas of distance. You’d look up a place and think, ‘Oh, it’s really far — yet, it’s only a few inches’. This reduced the immensity of the world into something more comfortable.

With marine maps, did human ideas about oceanic animals change?
■ Early European maps frequently had illustrations of ‘sea monsters’, most terrifying creatures scattered all over the oceans. Then, these ‘monsters’ started to decline — they slowly got wiped off the map as Europeans went out and saw these scary, unknown seas weren’t really inhabited by the amazing monsters they had imagined. A growing familiarity began then with species which actually lived in the seas — unfortunately, that also resulted in much more killing, particularly whaling. Mapping the ocean helped humans learn trends of where these animals lived and moved to. So, this became a double-edged sword. You gained knowledge of other forms of life — but some of these living beings got swept away in the process.

The Anthropocene is now impacting oceans via volumes of water, tides and sea winds — will this change human understandings as well?
■ Hopefully. We are in the UN Ocean Science Decade and I hope there is more appreciation of the planet as a whole. As we feel threatened, there is a growing thirst for knowledge about how nature functions. I hope the climate emergency encourages us to think of how the wondrous seas actually work.

The Anthropocene is a useful concept for historians to come to grips with a new attitude towards the world that starts in the 16th century. The idea grows that the world is there for people to use — and leave their mark on. Of course, your repeated activities will mark the world. This is what climate change shows. Similarly, if you build a map and use it to interfere with the natural environment, it will do exactly that. Hence, maps, brilliant and fascinating tools for knowledge, can also be used for destruction.

The history of charting is riddled with mistakes as well, from Columbus mistaking continents to people replicating incorrect islands. If you don’t know your real location, everything gets a bit skewed. These errors echo the Anthropocene — humans can grow arrogant but if you become overconfident, things will go wrong.