Water is a chemical substance that is the main constituent of the Pacific Ocean. It can also be treated as a beverage if purified for consumption. It appears in every episode of the series, but first appears in "Reef Blower" in individuality and "Tea at the Treedome" as a drink.
Water is a transparent, occasionally blue fluid liquid. It is the main constituent of Earth's hydrosphere and the fluids of all known living organisms. It is vital for all known forms of life, even though it provides no calories or organic nutrients. Its chemical formula is H2O, meaning that each of its molecules contains one oxygen and two hydrogen atoms, connected by covalent bonds.
Role in series
Water appears in every episode of the series and especially plays a vital role in helping the residents of Bikini Bottom and the Pacific Ocean in general stay alive, as they would dehydrate if the ocean's water was removed in favor of pure oxygen.
There exist water helmets to assist sea creatures in breathing while in Sandy's treedome, an air-polluted dome residence in Bikini Bottom in which Sandy Cheeks lives. Sandy herself regularly wears a helmet and astronaut suit when outside in order to survive since she is a mammal.
Water is the main component of the Pacific Ocean which is introduced in this episode.
SpongeBob sucks up all the water out of the ocean with his reef blower before the vacuum explodes and essentially restores the water in the ocean.
"Tea at the Treedome"
SpongeBob enters Sandy's treedome and immediately dehydrates due to the lack of water in the environment. He tries to absorb all the water in Birdy's bath fountain only to be pushed away by him. Sandy then puts the flowers SpongeBob bought her in a vase of ice-cold water while she prepares the tea and cookies. SpongeBob eyes the vase and continuously tries to convince himself that he doesn't need the water, taking Patrick's advice to stick his pinkie finger out as a symbol of strength, but the temptations start to weigh heavily on him before SpongeBob gives up and ultimately drinks all the water out of the vase, declaring himself a quitter. Patrick runs in to restore his strength, only for him too to dehydrate in the treedome.
Once Sandy is finished making the tea and cookies, she reacts frightened upon seeing a shriveled-up sponge and starfish on the ground. To compensate, she creates water helmets for the duo to help them breathe while in her treedome, serving them their tea through the helmets as well.
Water serves as a major plot point in this episode as SpongeBob tries to get Gary to take a bath. After many failed attempts, he eventually brings the bath to him by absorbing all the water in the bathtub and shooting it all over the house. Gary manages to miss each attempt.
SpongeBob goes to the kitchen to get a glass of water after choking on his eraser shavings and later cites drinking water among the 100 things not to do at a stoplight in his essay, referencing the incident earlier in the episode.
Mrs. Puff declares her love for being in jail based on the fact that she'll no longer have to deal with uranium, drinking a glass of crystal clear water in the process. She was originally going to state being away from SpongeBob as the reason, though she elongated the use of "you" and had to quickly think of a word with a similarly starting pronunciation to hide the truth.
Patrick consumes all the glasses of bubbly water in SpongeBob's refrigerator for brain fuel to concoct his plan for SpongeBob to attend the Mermaid Man and Barnacle Boy meet and greet with school in the way. He becomes morbidly obese increasingly with each bottle consumed.