>>33504656The bubble would need to be one strong enough to support the weight it's carrying and it would require a Primarina's voice to guide the bubble, so said Primarina would need to be outside of the bubble in order to command it going off the assumption that it would not be able to control the voice from inside. This would also most likely mean the Primarina has to be riding it, in order to be within close enough proximity of the bubble at all times. Provided these conditions are met, then I don't see why they couldn't.