Octetra was born in the North Atlantic Ocean, between our terrestrial and the celestial spheres. I had studied navigation and revelled in its practice: of drawing down sun, stars and planets to the horizon where our destination lay hidden.

We would follow a great circle, as a series of straight lines pencilled on the chart and calculate small circles of position from the angular height of stars and planets measured above the horizon with a sextant. This was world of angles, planes and time that would result in a cross on a chart and maybe a small course adjustment.

In the dark hours of a sea watch there is time to think, to contemplate the practice of navigation and more fully understand its theory. To see our planet as a ball in space, rotating as it rotates our star. To see those circles great and small, to understand their significance and creation as the planets move along the ecliptic highway.