While swimming yesterday to Gull Island during the late afternoon flood, I thought about orientation. Much of my recent scholarly work has focused on the challenge of orientation at sea in the early modern period, when the problem of landlessness caused many ships to arrive at places they’d never intended, including the bottom of the sea. The sun and stars helped, except on cloudy days, but mainly for latitude only, at least until the invention of Harrison’s marine chronometer in the 18c.
Being in the water rather than on it changed the kinds of data I could use to find my way across warm, slightly choppy waters to and from the island. I did use the sun’s glare, visible beneath the surface, by steering into it on my way back. But I also timed my swim through the gradual increase in the height of the swell, as I got farther away from the shelter of Kelsey Island, and also a dramatic change in water temperature. Once I finally cleared the wind shadow of the island — the wind was a bit west of south yesterday — the cooler water from out in the Sound blew in, and all of a sudden the temp dropped at least two degrees. It felt good, actually, to swim the last 300 yards or so in cooler, faster-feeling water, even though the swell was up too.
It made me think about things like color and salinity and depth and temperature, all roughly measurable by early modern mariners. Even if they didn’t have good thermometers yet — Robert Fludd may have built one in the 1630s, and Galileo at least knew how in theory, but I’m not sure when they first appeared on boats — one thing I proved to myself yesterday is that human flesh is a decent enough rough temperature gauge. There are all sorts of physical properties of water that can help place humans in the watery element.
Which makes the human body itself a kind of oceanic orientation device, an awkward and inefficient one, perhaps, but really we’re not very good at measuring or locating ourselves on land either.
Books about sailors’ craft, early modern and more recent, talk about “feel” and a mariner’s intuition. Maybe we need to take this sort of seamanlike feel more literally?