He knew in which direction to look. The Afrikander, if he still remained afloat, must be somewhere in the phosphorescent trail known as the ship's wake.
His quick eyes detected something floating about a hundred yards away, a round black object rising and falling in the undulations caused by the 16,000 tons steamer cutting through the sea at full speed.
Colin, pushing the buoy before him, swam towards the spot where he imagined Van der Wyck to be floating. Before he had covered half the distance he knew that his surmise was correct. It was his cabin-mate.
"Hold up!" he shouted, his voice sounding painfully feeble in the solitude of the night. "I'm coming to you."
Nearer and nearer Colin swam, pushing the buoy in front of him. Van der Wyck was floating perfectly motionless with his arms behind his head. Although he was unable to swim, he possessed sufficient confidence to lie on his back, keep his arms well submerged, and breathe regularly and deeply.
Nevertheless, he was unfeignedly glad to be able to grasp the buoy, but his surprise was unrestrained when he recognised Colin Sinclair. "How on earth——" he began, then, struck by the absurdity of the question, he added: "Did you fall overboard too?"
"Sort of," replied Colin. "Luckily the sea's warm. Wonder how long they'll take to pick us up. Hello, where's the ship now?"
There was no reply from his companion.
Colin repeated the question, conscious for the first time of their joint peril. The Huldebras was no longer in sight.