The jet pack is really cool! You have to watch a little 10 minute video, get suited up and you're ready to go. You don't really fly the thing, you just keep it steady and learn how to maneuver it. The throttle is controlled by a trained jetpack employee who speaks to you via headphones to give instruction on what to do.
The jets themselves are powered by seawater sucked up from the bay and then forced out the engines creating a thruster effect.
Needless to say, it's a very cool way to experience the water here in San Diego!