Big Trouble for Bulma is the twentieth episode of the Namek Saga and the forty-sixth episode of the original Saban dub for the Dragon Ball Z series. If The Tree of Might three-parter is counted then this episode is forty-ninth overall in the Saban dub.
In a fit of rage, Vegeta hurries back to the cave where he fought Zarbon. After searching through it and finding that Krillin, Gohan, and Bulma have gone, he returns to his hiding place and adds to his collection the Dragon Ball that he took from Krillin. Gohan, Bulma, and Krillin find a space between some mountains and decide to make it their new hiding place. Bulma is complaining about how bad Krillin smells, but he has better things to worry about. He is planning to take Gohan to see Guru so that he can awaken the boy's sleeping powers. Krillin believes that if Gohan's powers are awakened, then they can beat Vegeta! Both boys depart, leaving Bulma to keep an eye on their Dragon Ball. Vegeta sits on his Dragon Ball and pouts. He knows that Frieza may spot him if he flies away and looks for Gohan.
Bulma is sitting in a lawn chair when a blast comes out of nowhere and almost hits her! She looks up and sees Vegeta coming right at her...and he looks very mad. He demands to know where his Dragon Ball is, and the horrified Bulma points to the ball (It's by her chair.) and tells him to take it. Strangely, he doesn't see it and thinks she's fooling around with him. Vegeta is about to fry her to a frazzle when...Bulma wakes up, kicking and screaming, and realizes that it was a dream. Frieza is growing rather impatient, and he begins to fire wild blasts all around Namek, causing some serious earthquakes. Namek is shaking, and Bulma tries to hold on to the side of the mountain and keep her foot on the Dragon Ball. She is unable to do so, and the ball rolls into the sea. When the earthquakes finally stop, Bulma walks out to the sea and sees that the Dragon Ball is barely submerged. Not wanting to get wet, Bulma tries to use a stick to get the ball, but she only pushes it in further. However, Bulma realizes that underwater is a safe hiding place for the ball and decides to leave it there. But when she casually glances at her bleeper, she realizes that the ball is heading deeper and farther away fast.
In panic, Bulma runs back to the sea, and the ball is gone! She finally get a hold of her self, takes out a Dyno-Cap, and creates a mini-submarine. Feeling a little more in control, Bulma hops in and maneuvers through the water. She follows her bleeper, which leads her to a sea monster. Bulma is terrified, but sees something shiny on its back: the Dragon Ball. She fires a torpedo at it, and the thing turns away.
Luckily the ball rolls off its back and onto the sandy floor. Bulma is going down to get it when she notices a huge, beautiful pearl. With dreams of fame and endless attention in her head, she forgets about the Dragon Ball and goes to the pearl. Bulma tries to get her "hands" on it, but a disturbance in the water causes her to slip down deeper and deeper. The precious Dragon Ball goes down with her. Bulma watches as it settles among hundreds of other balls. Thinking that they are gigantic pearls, Bulma makes her way toward them. Out of nowhere, this giant crab comes up and catches her sub in its claws! Bulma manages to get away, but the crab is crushing everything in its path to get to her again! Finally, the crab backs off but only to watch the "pearls" break open and the baby crabs come out. Bulma realizes that the crab was only protecting her eggs, but a rock that the mother crab whacked is about to fall on the babies! Bulma races over to them, catches the rock, and holds it while the crabs crawl away. She then grabs the Dragon Ball and speeds toward the surface. Once on land, Bulma clings to the Dragon Ball wearily. The worst seems over when...two of Frieza's freaky henchmen appear over her, and they want the Dragon Ball.