The Dining Sock is an item that belongs to The Flying Dutchman. He uses the sock to eat with, and he cannot eat anything without it.
The Dining Sock is a regular blue-striped sock. It seems to be pretty durable since SpongeBob and the Flying Dutchman were pulling on it hardly. Though, The Dutchman tells SpongeBob to stop because he probably knew that too much pulling would "stretch out the elastic."
Role in the Series
SpongeBob and Patrick steal the Dining Sock in the episode "Shanghaied." The Flying Dutchman almost eats SpongeBob and Patrick. If they did not steal his Dining Sock, they would have been eaten in an unknown way or not even eaten at all.
It also made an appearance in "Your Shoe's Untied" in which the Dutchman mentioned that he sometimes wears it in place of shoes.