At Goo Lagoon, SpongeBob and Patrick are sunbathing. SpongeBob notices the adoration that the lifeguard, Larry the Lobster, receives. He fantasizes about how cool it would be if he was a lifeguard himself, but Patrick has no fondness for lifeguards and stomps off to the snack bar. SpongeBob declares that he's already as cool as Larry, and that nothing but an airborne ice cream truck striking him down could prove otherwise.
One collision later, Larry helps SpongeBob up and notices vanilla ice cream has been smeared on his nose. Thinking that it is sunscreen, and that therefore he is a lifeguard, Larry enlists the all-too-eager SpongeBob in helping him with his duties. As a lifeguard, SpongeBob becomes very popular and does many fun activities, and is happy to accept taking the second shift solo. However, Larry hears a swimmer drowning and saves him, and SpongeBob realizes too late that being a lifeguard is actually serious business.
His shift now over, Larry heads off for the tanning booth, leaving SpongeBob, who cannot swim, in charge of the beach. SpongeBob tries to laugh off his fears, but can't help but imagine the sea of swimmers in the lagoon as a sea of graves instead. In a panic, he alerts all the fish to an "emergency" and orders them out of the water. When asked what's happening, he declares that sharks have infested the lagoon, a comment that does not sit well with a kindly shark family in the crowd. He then raves about a sea monster, who gives SpongeBob a slap in the face. The frustrated crowd then disperses and heads back to the water, much to SpongeBob's dismay.
Stressed out from watching the beach-goers engaging in risky activities, SpongeBob resorts to luring everyone out of the lagoon with free ice cream. Once everyone has some to eat, SpongeBob points out that they must now wait one hour to re-enter the water, and binds them with police tape to enforce this rule. Patrick, who had been in the restroom, runs out in search of the promised ice cream. Misreading the police tape as a sign for ice cream, he breaks through it to go into the water, where he gets cramps and starts drowning.
While the crowd tries to alert SpongeBob to this real emergency, he initially refuses to believe them. However, he eventually sees Patrick and springs into action, desperate to find a way to save him without having to swim. He confiscates a boatmobile from the parking lot and rows it out, but Patrick destroys it and they both start drowning. As they say their goodbyes, Larry arrives in time to pull them up from the ankle-deep water. Having realized SpongeBob is no lifeguard, Larry sets him and Patrick to work practicing their swimming in a kiddie pool. They both wind up with butt cramps, Patrick still lamenting his lack of ice cream.
Even though the setting of the episode and the entire show is under water and Goo Lagoon is actually made of goo, not water, the goo is referred to as "water" several times in the series, for example when SpongeBob yells "Don't go into the water!"
The title card's background is the same background as the "Uhhh..." timecard in the episode "Rock-a-Bye Bivalve."
In the Polish dub, the episode's title is "SpongeBob ratownik" which translates to "SpongeBob the Lifeguard."
This episode hints that Patrick is so incredibly uneducated that he cannot even read properly, evidenced when he misreads the "DO NOT CROSS" isolation ribbon as "ICE CREAM." However, he could simply have imagined it as opposed to not reading it properly and in other episodes, he can read just fine.