Fish Out of Water is the fourth episode of season 3, and the 28th episode overall. It follows BoJack on his trip under the sea to promote his film.
Ana Spanikopita sends BoJack to the world's biggest underwater film festival to promote Secretariat. Unfortunately, ex-Secretariat director Kelsey Jannings is also attending. Faced with the thought of seeing her, BoJack panics: Not only will he have to have an awkward confrontation, he'll also have to do it underwater, where speaking is inhibited by his helmet.
When BoJack gets to his hotel room, he realizes two things: a confrontation with Kelsey is inevitable, and he will have to make it through without the help of cigarettes or alcohol. After he successfully avoids a hallway run-in, BoJack goes down to the festival lobby where press events are underway. He notices Kelsey sadly trying to drum up interest in her movie, so he tries to write her an apology note, but she disappears before he can give it to her. In the background, we notice that a big BoJack-related scandal appears to be breaking — the thumbs-up sign is a big no-no in Pacific Ocean City — but clueless to it all, BoJack chases after Kelsey. In doing so, he falls asleep on the bus and winds up far from the city, where he has to help a male seahorse give birth. As he starts his long walk back to the festival, BoJack realizes that one of the baby seahorses clung to him, so he reluctantly decides to find its dad.
BoJack doesn't have any local currency on him, so he's forced to steal seahorse milk from a shark-owned convenience store. The shark goes chasing after BoJack and the baby seahorse, forcing them even further from Pacific Ocean City, the film festival, and the chance to make things right with Kelsey. They find themselves plummeting into deep ocean (in a sequence that brings to mind the Rock Bottom episode of Spongebob Squarepants), and BoJack chases the baby seahorse through a neon seascape.
They follow what they think is a current into an undersea factory. Luckily, it's the freshwater taffy factory where the seahorse dad works. (This sequence leans hard into old-timey cartoon tropes.) BoJack saves the baby seahorse from being crushed into taffy, and though he raises the ire of the factory owner and guards, he's unable to reunite the baby with its father.
Cornered by the guards, BoJack falls out of the factory window, only to remember that he can swim underwater. With baby seahorse in tow, he goes flying toward the seahorse dad's house, where it turns out the kid wasn't even missed. The seahorse dad invites BoJack in for dinner, and even offers him money, but BoJack doesn't want any of it. The dad seems to ask, "What do you want?" but BoJack doesn't know. Has he ever known?
BoJack leaves, jealous of the seahorse family, and catches a cab back to the hotel. While in the cab, he writes a new note to Kelsey — this one much more heartfelt than the previous ones. He's too late to attend the premiere, so he goes back to the hotel just in time for the festival's opening-night party, where he learns that Secretariat was a huge hit. As Kelsey leaves the party, BoJack runs after her cab, but by the time he reaches her window, his soggy note is runny and blurred. Kelsey speeds off without knowing what he wanted to say.
As BoJack stands at a crosswalk, a man also with a helmet speaks to him by pressing a button on the collar. Realizing that he could speak the whole time, BoJack presses the button and the episode finishes with him saying "Are you kidding m-"
- This episode is almost entire dialogue free once it gets to the underwater scenes.