

For a water powered jetpack to lift a person it is estimated to need at least 100 gallons per minute, so similarly this could be what would be needed. Even for a second, a person’s bladder would need to be 1.6 gallons and expelled at a similar pressure. So not two seconds.
Lemmy apps: https://join-lemmy.org/apps. Good for desktop: Voyager. (Web app closest to mobile experience on desktop)