The Beach Ball! is the tenth episode of Season 2 and the 30th episode of the series.
Molly and Gil head to the beach where they hear from their friend Sandy about a party that she may not go to because of her work. The Guppies argee to go while they learn all about the beach and what you can do there.
Molly greets the audience before trying to say, "its time for bubble guppies" but she hears someone saying something and swims over to see Gil building a sandcastle. Everytime Molly tries to say it, Gil would say "One more" until the huge sandcastle falls on top of him! Molly checks on him when he suddenly pops out to say "It's time for Bubble Guppies!"
Molly, Gil, and Bubble Puppy are on their way to school when a beach ball rolls over to them. Gil returns it to the little lobster child and they realize they're by the beach! Molly and Gil both love going to the beach and since they have a moment they swim by it to see a bunch of people there. They come to a shack where a girl named Sandy offers the customer a coconut drink. She explains to Molly and Gil the party that evening and at the end of the night one lucky dancer will be crowned Queen of the Beach! She wants to go, and Molly thinks she is a good dancer but Sandy's sisters unfortuantly tell her she can't attend the Ball because she needs to prepare all of the coconuts for the Ball. Molly asks if her sisters plan to help her, but Sandy informs Molly that they never do, so she'll just have to miss out... Molly and Gil then head to school realizing its time to go. Sandy says farewell to them and resumes work.
At school, Molly and Gil explain how they met a really nice girl named Sandy and they all begin to discuss things to do at the beach. Like using buckets of sand to build sandcastles, or collect seashells. This inspires the Guppies to sing "At The Beach".
Gil and Bubble Puppy wish to buy seashells and they go to Deema's shop where she informs them she is having a special on matching shells. Gil and Bubble Puppy can have any seashells that look exactly alike. Gil sees two matching blue shells and then two purply-blue conch-like shells. Gil thanks both Deema and the audience for help. Mr. Grouper decides it must be Lunchtime! Nonny with the lunch joke: spaghetti and beach balls.
Molly talks about all the fun things to do at the beach when she sees Gil trying to find seashells. He picks a couple up, and Molly mentions that if you hold certain shells up to your ear, you can hear the ocean. Suddenly the shell moves as Gil tries to grab it and he ends up swimming off screen after it!
In class the girls and Mr. Grouper are having fun dancing! Nonny asks Mr. Grouper if he bothered to put on sunscreen and Mr. Grouper turns bright red and pretends to have sunburn, but he is only kidding and explains that he ALWAYS puts on sunscreen. Molly then passes out some Coconut Water and Mr. Grouper decides its time to go outside!
Oona and Goby are two surfers who go to surf at the very cold beach in the Arctic. But before they could get their surfboards into the water a Polar Bear scares them away when he claims it is his beach. So the surfers run away to find another beach, but again the polar bear shows up and says it is his beach. Oona tries to tell him its for everyone but he won't listen and soon they find themselves on the edge of an ice part. They break it off and manage to float away from him. Oona believes they are safe... until seeing he has an innertube!
Seeing a big wave, Goby points out that if they had their surfboards they could just surf on it to get back to the shore before the polar bear gets them. But since they do not have them, Oona and Goby make a surfboard out of ice to swim the giant wave!
So, Goby and Oona then proceed to surf the wave as the polar bear tries to get them but he slips out of the wave. The two surfers managed to get back to the shore when the polar bear confronts them. He then says what they did was awesome and asks what Surfing is. He really liked it and asks for Oona and Goby to teach them. Oona says they'll teach him but ONLY if he promises to share the beach. So the two surfers and the Polar Bear lived happily ever after... Then Gil sings The Swim Dance
Molly loves to dance, and she hopes Sandy will get to go to the beach ball tonight. Gil then whispers to her that he is trying to sneak up on the shell and hear the ocean. When he tricks it he tries to listen but a hermit pops out and pinches him! Then runs off.
At the beach ball that evening the Guppies quickly notice that Sandy isn't there anywhere. Molly tries to look for her, then asks Sandy's sisters if they know where she is. They inform her that she didn't come to the ball since she has a bunch of work to do. Molly asks if she's the only doing the work, which makes her feel very sad and she leaves to find Sandy by herself preparing the drinks. Molly asks why she isn't at the ball, to which Sandy mentions she has to do all the work still.
Molly offers to help and all the guppies, Mr. Grouper, and Bubble Puppy show up to lend Sandy a hand! They all then sing the Coconut Water song and in no time they all manage to finish! Sandy thanks them and they all go back to the Ball to dance and hand out the drinks. After they finish dancing the judge announces the winner. But he informs that there's two queens, not just one: Sandy and Molly!
Sandy thanks Molly and the other guppies for helping her when Sandy's sisters come over and apologize for being so mean and not helping her. They congradulate her, then Sandy is asked if she wants to say anything and everyone resumes dancing as the episode ends!
Molly is very happy that Sandy won and Gil congradulates her. She points out the shell and Gil says he wont fall for the same trick twice. He picks up another shell and out pops a tiny clam saying "momma!" Gil then looks behind him to see a very big clam and it chases him!