It was massive, immense beyond anything that Oscar had ever seen. It was said to have a radius as wide as one AU, and it was as wide as Earth, but only about a mile thick.
It must have been made of something incredibly strong to survive this must stress and pressure.
Oscar swam away into the sea.
"Best not to worry about this", he thought.
He leapt out of the sea of Ringworld and quickly reached superluminal speeds.
He slammed through the sun and landed on the opposite of Ringworld. Which was coincidentally a sea.
THE END