Island Hopping is a rather difficult application of the Item Sliding glitch. If you charge up an Item Slide for long enough and release your speed with the correct timing, you can hop between islands on the overworld. This is useful as some islands do not allow Link to superswim away from them since they don't have slopes which lead into the water. Most Island Hops are executed by Wall targetting a specific part of the island you are on and using that angle as a means of lining up the island hop, which can then be executed by charging up an Item Slide and then pressing ZL with very specific timing to shoot Link right or left (depending on his speed). Since there are no visual or auditory cues for this timing a metronome is usually used to consistnetly time Island Hops. The metronome tempos runners use are dependent on the ESS position of the Item Slide being as small as they can possibly be for the greatest speed acceleration.