what role does santiago's skiff play in the story?

Santiago's skiff is an old decrepit boat. The other younger fishermen laugh at it. They have bigger boats with motors and radios. The skiff represents the old man. It is tired and old, just like Santiago. There is a futility about the boat that represents Santiago's struggle to recapture his youth. The sail of his skiff struggles in the air : it represents, “the flag of permanent defeat".