A deep physical booming woke me in my bunk. For a moment as I emerged from a dream, it was as if some Grendel, a manifest monster, was trying to enter my waking world.  It was a pounding on the steel structure of our ship as the Antarctic swell objected to our presence.  And the wind whipped our sails, angry at the theft of its moving energy, creating a roaring counter tone.

As we chew through the rolling roiling sea between the Falklands and South Georgia, bite by bite, I am becoming conscious of the marginal manner by which the Europa exists. The ocean is thousands of metres deep and we float on the top three or four. Our keel knifes the liquid, cutting it in a constant continuum. The atmosphere stretches above us to space, but we barely touch the first meagre few metres of it. Our masts are great grabbing fingers grasping upwards to glean the moving molecules of air. We function and fight at the fundamental meeting of sea and air, in a balancing equation carefully calculated by captain and crew. But we are miniscule, mounted on the maritime margin.  In this storm, snow and sleet, spray and spume blur the boundary.  We think of our globe as a solid entity in space. But there is only liquid and air here. We are on the edge of both, at the edge of the world indeed.