then , with the oar handles up close to his chin and the oar tips at maximum extension away from his body , his hands holding the oars would drop toward his lap , lifting the tips out of the water , and hed reverse the former sequenceraising his upper body toward vertical , loosening his calves and thighs and shifting his body toward the rear of the boat as he extended his arms away from his center of gravity and the oar tips floating above the water angled toward the bow of the boat .