Why did Brandon the Shipwright sail west? What did he have to gain from it beyond losing a bunch of ships?

“Lord Gylbert began to speak. He told of a wondrous land beyond the Sunset Sea, a land without winter or want, where death had no dominion. “Make me your king, and I shall lead you there,” he cried. “We will build ten thousand ships as Nymeria once did and take sail with all our people to the land beyond the sunset. There every man shall be a king and every wife a queen.”