When they were younger, the Aquatic Adventurers were a famous superhero team with a comic book series dedicated to them that detailed some of their battles, with one such battle being the time they faced the Invisible Isopod. SpongeBob states that they are his favorite superhero team.
Every year after they disbanded, the members of the Aquatic Adventurers get together to hold a reunion. This tradition has continued at least 75 years, and the team held their 75th reunion in the Krusty Krab. Though they are old at this time, they are still capable of fighting any villain that tries to attack them (as shown when they pummel Mr. Krabs after mistaking him for the Invisible Isopod).
Role in comic book
In the comic Lo, There Shall Be A Catered Affair!, Mr. Krabs says that the Aquatic Adventurers will hold their 75th reunion at the Krusty Krab. SpongeBob wants to get them to sign his copy of the team's first issue of their comic book series, but Mr. Krabs forbids it. However, Mr. Krabs himself wants the team to sign his copy so that he can sell the book for profit.
That night, the superhero team arrives and SpongeBob barely resists making a fool of himself in front of them. Mr. Krabs takes the Flying Fish to sign his comic book, and everyone notices he is gone. SpongeBob compares this to the story in the heroes' comic book, where the heroes are attacked by the Invisible Isopod, who plans to abduct them one by one.
As Mr. Krabs takes the members of the team to sign his comic book, SpongeBob and the rest of the Aquatic Adventurers fully believe that the Invisible Isopod is attacking them. After SpongeBob gets scared by a mailman, he suggests that the team are too vulnerable and should hid somewhere where they can't be surprised. The team agree, so SpongeBob and the team hide in the bathroom.
As Mr. Krabs searches for everyone, he opens the bathroom door and is attacked by the Aquatic Adventurers, who think that he is the Invisible Isopod. As the team realize their mistake, they bemoan the fact that the Isopod never attacked, as it thrilled them. Barnacle Boy then says that he knew the Invisible Isopod was never attacking them, until he is wedgied by the Invisible Isopod as everyone looks in shock.
The Aquatic Adventurers then appear in a bonus gallery poster later in the same comic book, alongside nearly every other Mermaid Man hero to exist.