What is the effect of the scene of the men who wave from the beach in "The Open Boat"?

The effect of the scene where the men wave from the beach in Stephen Crane's "The Open Boat" is contradictory. Four men are stranded in a small lifeboat on the rough seas, and they are looking for any glimpse of salvation. When they see the life-saving house and later see the men waving, this gives the men hope that they will be saved. If someone sees them from the beach, surely they will be rescued, they think. At first they are exhilarated by the possibility that the people waving on the beach will send someone to save them. However, later, when they realize that the people waving are not waving at them but are simply people on an omnibus who don't see them, their hope is dashed. So while at first the people gave them hope, they later made them lose hope. Indeed, no one on the beach sees them--we realize this by the end of the story.