Early Master Sword (EMS) is a sequence break that allows you to get the Master Sword before completing the Tower of the Gods and the first visit to Hyrule. This is done by activating the cutscene in Ganon's lookout during the second visit to Forsaken Fortress which will give you the Master Sword if you do not have it already. Although this may seem incredibly useful, it leads to a dead end as discussed below. However, since the Master Sword does twice the damage of the Hero's Sword, it can be useful in speeding up battles in some individual level runs.
Because it is not possible to defeat Phantom Ganon in FF2 without the Master Sword, it is not possible to obtain the Skull Hammer early. This sequence breaks can be broken down into 3 parts: Visiting FF2 before beating TotG, entering the Helmaroc fight without the Skull Hammer, and Helmaroc Skip.
Because the courtyard cutscene in Hyrule 2 causes a crash if you haven't unlocked KoRL, you MUST beat FF1 before doing this sequence break. If you can find a way to skip the courtyard cutscene without having to unlock KoRL (for exemple by obtaining the triforce early before unlocking KoRL, which is not currently possible), you would be able to skip FF1 for this sequence break, but there is no known way yet.
Superswim is a much faster way to access FF2, and makes this sequence break more practical for use in Individual Level speed runs. Get dry storage off of the rocks to the right of the docks on Windfall. When building up speed for your superswim, you may want to start off in the water by the docks, as you will almost assuredly get more than one air refill. However it is also very likely that you may hit land or grab the dock and have to restart your superswim.
Once you have built up a fairly substantial amount of speed and your air meter begins to turn red, use your sea chart to make sure that you are aligned so that your back is towards Forsaken Fortress and release the control stick. If you've built up enough speed, as you enter the quadrant of Forsaken Fortress, you will fall and get an air refill. If not, you will have to try to swim to one of the indentations in the rocks along the fortress's base where you can refill your air meter.
Now comes the tricky part: pulling yourself up onto the rocks so you can fix the crazy camera and get into FF2. There is a rock the is slanted into the water that you can use to pull yourself up (refer to the video below). Hold L so that you can swim here without charging up a superswim, and then hold straight up on the control stick to spin around and grab the ledge. Once you've pulled yourself up, pull out the wind waker to fix the camera and use a wind waker dive to get into the fortress and swim over to the inner-fortress loading zone.
Alternatively, you can use this other spot to dive into the fortress:
Note: If you save and quit/reset before reaching the Helmaroc battle, you will be taken to the King of Red Lions who will then automatically sail you back to Windfall. Avoid making this mistake!
Although it is possible to reach Forsaken Fortress a second time via zombie hover from Windfall, this is an extremely long hover that will take multiple hours to complete and is only possible if you have the Tingle Tuner. However, with the discovery of dry storage it is now possible (and much quicker) to use superswim to get to FF2 early.
With chest storage, you can climb up the wall before the first sidle gap to reach the door leading to the Helmaroc fight faster, while avoiding the Phantom Ganon fight completely. Since you have chest storage, you can skip the hammer peg by entering Helmaroc early, by jumping behind the door. The deku leaf helps but isn't required. A few different routes are possible:
In order to skip the hammer pegs all around the fortress without chest storage, you can do two different things:
Store the door leading into the Moblin Room. Climb ontop of the grapple spot above the second sidle gap. This will trigger the Phantom Ganon cutscene, but don't worry, you will still be hanging from the grapple spot. Climb up, pull out the wind waker, and immediately cancel it and pull the leaf. The game tried to teleport you back to the door you stored and made you clip OoB. You only have to leaf behind the door and into the loading zone leading to the Helmaroc fight from there.
Sail to the left side of the entrance to Forsaken Fortress. Climb up onto the rocks and walk over towards the blocked entrance where the rocks dip down. Now walk towards the edge and pull out the Wind Waker to Wind Waker Dive. Wait about until the first count on the Wind Waker's scale and swim over behind the large wooden door. This skips obtaining the Skull Hammer and battling Phantom Ganon.
After getting to the pictured searchlight, call Tingle and make sure that the wind is blowing southeast. Align yourself with the appropriate angle and zombie hover. After starting the hover equip a red ting to B on the Tingle Tuner. Once you have passed through the wall above the door to the Helmaroc King battle, press B on the Tingle Tuner. Right before Link is given the ting, tap the Deku Leaf button and leaf into the loading zone.
Now perform one of the various Helmaroc King skips and complete FF2.
Right after beating the Forsaken Fortress 1, the game is put either into layer 0 or layer 8 depending if it's the first time you're watching the cutscene or not. On that layer, there are no spikes, no Phantom Ganon battle and no door in the Forsaken Fortress quadrant. This can be used to perform Early Master Sword: simply superswim to FF2 from Windfall and climb the fortress while making sure you are not reloading the area, since that would reset the layers. Once on top of the fortress you can simply walk through the non-existent door and enter the loading zone leading to the Ganondorf fight.
In order to delay beating FF1, you can either perform Outset Escape, or you can skip the Gossip Stone Trigger during your first visit to FF1, which skips having to progress the state of the pirate ship. That way you can go swordless upon going back to FF1 via the pirate ship (only if you've watched the Barrel Launching cutscene), and once swordless, you can get caught by lantern moblins to re-enter FF1 for real.
On the japanese version, playing the Flight Control Platform minigame puts the overworld on layer 1. By playing the Song of Passing on layer 1 you can reach layer 0 and go to Forsaken Fortress 2 where the door will not exist.
See the Helmaroc King page.
Although you will not encounter and problems with getting the Master Sword early at first, there is a major dead end that occurs which prevents you from being able to destroy the barrier leading to Ganon's Tower. Once EMS has been used, it becomes impossible to draw the Master Sword from what is normally the first visit to Hyrule. Though this may not seem important, drawing the Master Sword from Hyrule 1 is one of the flags that triggers the breaking of the barrier cutscene in Hyrule 3.