Rocket Pump, also referred to as Rocketboarding or more commonly Pocket Rocket is a technique utilizing Fuse Entanglement in order to attach a rocket to Link's shield but not be completely loaded onto the shield allowing for an instant cancel out of a shield surf causing Link to repeatedly and (near) infinitely jump.
Before doing Rocket Pump it is important to understand some of the ideas and properties of the technique. Pocket Rocket works by attaching a rocket to Link's shield while holding the rocket in some other way (i.e., Autobuild, Fusing to equipment) it technically does not have to be attached to anything but after just a couple of pumps away from the rocket and it will despawn causing the rocket to no longer be "attached" to the shield. It is also important to note that this technique is not limited to rockets and can be used with many other Zonai devices and materials. The only other thing to note is that this technique will still use shield durability and your battery so it is not just an infinite jump but is still reliant on what you have which is why many people perform this glitch with the Hylian Shield.
You will need two Shields, the Fuse ability, a Rocket, and any fusible melee weapon/Autobuild to perform this.