At Goo Lagon, Spongebob and Patrick are sunbating at the beach in Bikini Bottom. Spongebob remarks on how cool Larry the Lifeguard is, and Spongebob fantasies how cool it would be if he was a Lifeguard, but Patrick doens’t agree. Spongebob then says that he’s just as cool as Larry, and he said that :
“ If I’m not, let me be struck by thunder crushes (a flying ice cream truck)! “
One day and accidentally the truck falls on him and he gets vanilla ice cream on his nose. Well, Larry who is the main lifeguard at the beach, sees this and assumes that Spongebob is really a lifeguard. Before he can even get a chance to explain to Larry that he really isn’t, he is asked to watch the beach for the rest of Larry’s shift so that he can leave for a little bit. Spongebob has always dreamed of being a lifeguard, so he takes him up on his offer, though he has no idea of what he is doing.
As a lifeguard, Spongebob becomes very popular and does many fun activities. Spongebob realizes that being a lifeguard is much more than giving them ice cream, and sitting in a tower, but it also mean you have to guard other people’s lives. Larry suddnely leaves for a tanning booth, leaving Spongebobo.
Everything seems to be going as it should until Spongebob gets really paranoid that something is going to happen. SpongeBob begins panicking when he sees everyone playing in the water in a dangerous way, such as people splashing each other, people water skiing on top of each other, two kids playing with a ball inside of a killer whale's mouth, and Frank throwing Scooter into a rock. So he tries to close down the beach. SpongeBob then lures everyone out of the water with ice cream. After they eat it, he tells them that they now have to wait one hour before going back in the water and binds them with Police tape. Thinking that everyone is safe, SpongeBob settles down to relax.
After that, Patrick decides that he is going to walk right into the water. But, he doesn’t really know how to swim and then he starts to drown. There is no one who can save him expect Spongebob, who doesn’t know how to swim either. Spongebob tries everything to get Patrick out of the water, but nothing seems to be helping. However, the beach guests get upset at this and one fish announces that Larry is a better Lifeguard than SpongeBob is.
SpongeBob announces that he gave them ice cream, and Larry never did. But Patrick, mistakenly looks for ice cream after SpongeBob says "ice cream" through a megaphone, crosses the tape after he sees the words on it as "Ice Cream", when it really is "Do Not Cross", and goes into the water, where he gets cramps and starts drowning. When other fish get alerted to this, SpongeBob initially refuses to believe that someone is drowning, but he eventually sees Patrick and tries to find a way to save him without going in the water. He reaches Patrick using a boatmobile he "borrowed" from the parking lot, but Patrick destroys it and they both start drowning. Larry then comes back and "saves" them from the ankle deep water.
Finally, he decides that since he is a sponge he is going to suck up all the water, but he is unsuccessful. Larry returns finally and is able to save Patrick from drowning. Spongebob admits at the end of the episode that he really did not know how to swim. Then Larry decides that he needs to give them swimming lessons. At the end of the episode, Larry is seen teaching the two how to swim, and they both get butt cramps.