The Great Pacific garbage patch is a zone in the Pacific Ocean where garbage has piled up on the surface. It appears in the episode "High Sea Diving."
It is a pile of live-action garbage that covers a vast area of the ocean. In the episode, it is shown to be really close to Bikini Atoll.
Role in episode
When SpongeBob uses balloons to high sea dive to the ocean's surface, he bumps into the garbage patch, which blocks him from the surface. He starts exploring the garbage patch, accidentally dislodging garbage that ends up landing in Bikini Bottom. He soon meets Old Man Jenkins, who claims to be King Neptune.
The two soon start flinging trash at each other, causing more trash to float down into Bikini Bottom. The Bikini Bottomites start to believe the trash are gifts from King Neptune and send gift requests via balloons. Said balloons float to the garbage patch and pop near SpongeBob and Old Man Jenkins, the latter wanting to go to Bikini Bottom to help his "subjects."
SpongeBob quickly uses the remaining garbage in the garbage patch to build a ladder down to Bikini Bottom, and quickly places the buoy marking his successful high sea dive to the surface. The Bikini Bottomites start climbing the ladder in hopes of meeting King Neptune, but instead find SpongeBob and Old Man Jenkins. The Bikini Bottomites thank SpongeBob for sending the "gifts" and rock the ladder while celebrating, causing the ladder and everyone on it to fall to Bikini Bottom.