Sure, we all love jet packs. Who doesn't enjoy strapping a gigantic tube of highly flammable fuel to their back
and igniting it so it can propel you hundreds of feet into the air? Well, an inventor named Raymond Li has a different idea, one which he's just managed to patent: a water-propelled rocket pack. The new design would use a system of conduits which route pressure to independently pivoting thrust nozzles, while the actual engine, pump, and dangerous gases remain floating on water in a self-contained, buoyant package. It's somewhat unclear if you'll be able to rocket over land using this device (the fact that the engine is water-based would suggest no), though it is an interesting development for jet-pack enthusiasts.