this is a pair of cuplets from the then Vice Chairman Ling Biao. Mao at that time was always viewed as the sun. The cuplets reads: To sail smoothly on the ocean, we depend on the captain! The next one is: All plant grow depend on the sun. It's a cool artist and collector's inkstick. Da Hai Hang Xing Kao Duo Shou is the way to read it in Chiense. Lin Biao was hand picked by Mao as the person to take over. But he was kind of went side tracked and on the way escaping to Russia, he was shot down. The slogan means Sailing on the rough sea needs a good captain.