The cartoon begins with a message to the audience: "Any resemblance to the poor fish in this photoplay either living or at Santa Anita is purely co-incidental." Then, a voice begins to explain what the viewer will be seeing in this cartoon. The ship has a glass-bottom so that one can see the many fish and aquatic life that live in the ocean. The ship "slowly" approaches the shore. The voice introduces Professor Mackrel fish-face. A man who steps into the diving device to search for the rarely known, legendary whim-wam-whistling shark. A shark that has never been caught by man before.
Viewing through the glass bottom pan, one can see the school of sardines, tightly compact together as if in a can. Then a tuna that acts like a chicken. The tuna then lays many eggs. Crabs come from the crustacean family and the old crab tells the viewer to mind their own business. Then he shows the viewer a hermit crab, reading a book titled "How to live alone and like it". And then a little taxi cab comes by.
The viewer then sees a dainty little starfish who dreams of becoming a famous actor. And then an electric eel flashing the message "Eat at Joe's" before a strange, two headed fish swims by, eager to be seen. The fish apparently have a question and both tell the other to ask the voice a question they have. They both ask the voice if they could be given directions but he tells them to leave instead. And then he continues, discussing a Polynesian dog fish but the little shell fish it was barking at scared it away.
A menacing fish turns to the side to show-off his fins, apparently composed of dollar bills. The professor meanwhile is still trying to find the shark so the voice continues.
He then views an octopus, about to attack a harmless little fish, but is startled away when the little fish goes "boo!". The voice continues, telling off the strange two-headed fish again before he discusses a well-known subject to the clam family, a mussel. Then onto the pickled herring, which seems to have gotten drunk. It walks right into a whales mouth as the whale winks to the viewers and the herring quickly swims out.
Nearby a bunch of seahorses are preparing for a race. The two headed fish appear again and try to ask him, but he responds by telling them to go and lay an egg. The two headed fish leave, then return a second later with two eggs!
Moving onto the shark territory, the voice talks about the tiger shark and how dangerous it is, until it meows at the audience. Then there is a hammer-head shark, which hits itself repeatedly with a hammer. Further down is a shovel-nose shark. The professor has now reached the lower area of the waters but is still in search.
The voice comes across a school of fish. The teacher explains that one is to approach the hook from the underside, as well as a double-twist. But he warns them how NOT to approach the hook but he accidentally gets hooked in the process. A school dismissed sign then comes back down and the school fish run off. The voice mentions that it's pretty late so they may need to leave behind the professor, but just then someone or something whistles!
The professor gets out of his aquatic sphere and sees a few eyes in the nearby cave. The professor runs into the sphere and grabs his net before he manages to get the shark. The voice happily prepares to show the professor, as well as the shark...
Just then, as the sphere opens, the shark is shown to have eaten the professor! He tips the professor's hat, and says to the audience, as Bert "The Mad Russian" Gordon, "How DO you DO?", as the cartoon ends.