Water helmets are equipment created so that water breathers can come into Sandy's treedome or any place with no water. They first appear in " Tea at the Treedome," coinciding with the first appearance of their creator, Sandy Cheeks.
They are transparent, circle-shaped helmets filled with water, worn by sea creatures so they can be in Sandy's treedome. They also come in various shapes and sizes to comply with certain sea creatures.
Normally the water helmets have one opening in the bottom, but in "
Tea at the Treedome," " Chimps Ahoy," " Squidtastic Voyage," and " What Ever Happened to SpongeBob?," they have two openings, one in the bottom and one at the top.
Role in series
Sandy originally used water helmets for SpongeBob and Patrick when they shriveled up in "Tea at the Treedome." Later, they were used conventionally for any sea creature who came to her treedome.
They are similar to Sandy's air helmet, which allows Sandy to breathe underwater similarly to how water helmets help sea creatures to breathe in her treedome.
The water helmets bear a striking resemblance to fish bowls.
In , The SpongeBob Movie: Sponge Out of Water Plankton uses a glass of water to go into Sandy's treedome because they do not make water helmets in his small size.
Mr. Krabs does not need a water helmet to enter Sandy's treedome in " The Krabby Patty That Ate Bikini Bottom," since he is a crab. Crabs can breathe both air and water, but Mr. Krabs still inexplicably wears a water helmet in " Overbooked," " Surf N' Turf," and " Hiccup Plague."
In " Pranks a Lot," when SpongeBob and Patrick are hiding in a sheet in Sandy's treedome, their water helmets are not seen in the said sheet.
The water helmets do not appear in season 3 or season 10. The treedome does appear once in both respective seasons, however.
In both " It's a SpongeBob Christmas!" and " The Legend of Boo-Kini Bottom," whenever SpongeBob and Patrick enter the treedome, they are able to breathe perfectly fine without dehydrating.
In " House Sittin' for Sandy," SpongeBob is able to go much longer without dehydrating in the treedome than usual until Patrick brings up his lack of a water helmet before putting one on SpongeBob.