IMAGINARY ISLANDS

EXPLORING THE SOUTH ATLANTIC AS A CELESTIAL NAVIGATOR TURNS INTO A THREE-YEAR QUEST FOR A LITTLE-VISITED ARCHIPELAGO

- KATE SCHNIPPERING

One foot east, one foot west. I stand on a line inscribed in stone: the Prime Meridian, longitude of zero. This threshold marks a rite of passage for becoming a celestial navigator. It’s April 2023 and I’ve journeyed a long way to the UK for my RYA Yachtmaster Ocean exam, where I'll be extensively questioned on the South Atlantic passage I sailed the previous year with Vinson of Antarctica, and on the ins and outs of my navigational records.

I’d spent six weeks aboard the expedition vessel, first learning the basics of wayfinding by sextant from shore, and then putting it into practice on a 4,000-mile downwind delivery strewn with storms and turbulent seas. I didn’t realise then, but I was embarking on an even bigger journey that would take three years to complete.

One year in, I’m warming up by visiting Greenwich Observatory to see first-hand the chronometers of John Harrison, who solved the challenge of determining longitude at sea in the 1700s. As I admire the exquisite pocket watch, I imagine H4 ticking away on a creaking old ship, faithfully telling Greenwich time and keeping the rocks at bay. Nonetheless, the Royal Society was unimpressed by this mechanical solution, and they withheld Harrison’s prize for more than 20 years, believing a more elegant answer lay in calculating the moon's paths. Today, we navigators consider the moon the least reliable object to take sights of!

Beyond the allure of duelling mathematical proofs, I’m fascinated by the earlier timepieces built to time's variable rhythms. Sundial rings. Tide-watches. A Nocturnal star-clock with an extended pointer to touch time on your skin at night. I want to feel a connection with Greenwich in my bones, so perhaps someday I won't need a timekeeper to know my longitude.