Their fears seemed to be rather well-founded.
Three hours after landing, Bordman moved gingerly over grayish muddy rock, with a four-thousand-foot sheer drop some twenty yards away. The ragged edge of a cliff fell straight down for the better part of a mile. Far below, the sea rippled gently. Bordman saw a long, long line of boats moving slowly out to sea. They towed something between them which reached from boat to boat in exaggerated catenary curves. The boats moved in line abreast straight out from the cliffs, towing this floating, curved thing between them.
Bordman regarded them for a moment and then inspected the grayish mud underfoot. He lifted his eyes to the inland side of this peculiar stretch of mountainside muddiness. There was a mast on the rock not far away. It held up what looked like a vision-camera.
Young Barnes said:
"Excuse me, sir. What are those boats doing?"
"They're towing an oil-slick out to sea," said Bordman absently, "by towing a floating line of some sort between them. There isn't enough oil to maintain the slick, and it's blown land-ward. So they tow it out to sea again. It holds down the seas. Every time, of course, they lose some of it."
"But—"
"There are trade winds," said Bordman, not looking to sea-ward at all. "They always blow in the same direction, nearly. They blow three-quarters of the way around the planet, and they build up seas as they blow. Normally, the swells that pound against this cliff, here, will be a hundred feet and more from trough to crest. They'll throw spray ten times that high, of course, and once when I was here before, spray came over the cliff-top. The impacts of the waves are—heavy. In a storm, if you put your ear to the ground on the leeward shore, you can hear the waves smash against these cliffs. It's vibration."
Bares looked uneasily at the cliff's edge and the line of boats pushing over an ocean whose waves seemed less than ripples from nearly a mile above them. But the line of boats was incredibly long. It was twenty miles in length at the least.