Outside the Krusty Krab, Mr. Krabs receives a letter from his grandfather who is visiting him. He is a pirate, unlike Mr. Krabs, who he thinks is a pirate also, instead of owning the Krusty Krab. Mr. Krabs tells SpongeBob that he was a pirate too like his grand-dad "Grandpa Redbeard" but he quit because his crew took all the money, and then he fired his crew. To please his "grandpappy," Mr. Krabs gets himself, Squidward, Patrick, and SpongeBob to disguise as pirates, rebuild the Krusty Krab into a pirate ship, and try to convince him that they are trained pirates.
Ironically, Grandpappy arrives and sees the ship and reveals that he was beginning to think Mr. Krabs was lying to his "old granddad." Grandpappy soon orders Mr. Krabs to show him what his ship can do. Mr. Krabs pretends to sail the ship. Squidward makes it look waves are coming up. Patrick blows water up in the air for effect. Mr. Krabs has to make a comment twice to get SpongeBob to do his part. SpongeBob's job is to play a record secretly (It is to make it sound like wind). Grandpappy is still fooled.
Grandpappy sees someone ahead and soon gets his "crew" to go to their stations for battle. Mr. Krabs is worried that it is the real deal. Mr. Krabs reveals it is his daughter, Pearl. Grandpappy, thinking it is a sea witch, claims he going to make her meet her maker. Before he can kill her, Mr. Krabs stops him just in time. Grandpappy asks Mr. Krabs why and Mr. Krabs responds he is only trying to inspect the "cannon." The fiery "cannon" is actually a fiery bag, as shown. Grandpappy wonders why it is so.
Pearl is angry because Mr. Krabs didn't come quickly. Mr. Krabs soon manages to shoo Pearl away. Mr. Krabs lets Grandpappy know that he has already taken care of it. Grandpappy sees through Mr. Krabs game and becomes so infuriated that the record on his nose literally explodes. Mr. Krabs tries to reason with him, but Grandpappy makes Mr. Krabs say that the code is to never tell a lie. Mr. Krabs says that he's a dirty liar.
Mr. Krabs breaks everything that is a lie and takes off the "crew"s clothing. The only thing left is the Krusty Krab and its true belonging. Mr. Krabs reveals to Grandpapy that he is the boss of a restaurant. Surprisingly to Mr. Krabs, Grandpappy is impressed for his effort of Mr. Krabs' restaurant saying that his prices of things and scamming people out of money legally is true piracy. Soon, Grandpappy "borrows" some of Mr. Krabs' "booty." Grandpappy leaves on a lifeboat, laughing maniacally like a pirate would do normally. Mr. Krabs, chuckling, says that he (himself) knew he got his talent from his Grandpappy.
When the mailman gives the letter for Mr. Krabs, the Krusty Krab sign is misspelled as "Krysty Krab." Also, the y is backwards.
In the scene when Mr. Krabs was a baby, he had no nose.
In the episode "Krusty Krab Training Video," it says that the Krusty Krab was formerly a retirement home, and its sign says the Rusty Krab (later painted, Krusty Krab). During the flashback when Mr. Krabs sells the ship, he has the Krusty Krab sign. This means the sign was either made before the restaurant, or the sign came from the ship.
In the shipbuilding montage, the Galley Grub is covered up, but later, the phrase, "Galley Grub" can clearly be seen in the background.
When SpongeBob jumps up to catch the harpoon, he is wearing his normal clothes, but when he next appears, he is wearing his pirate outfit again.