After the initial FF1 cutscene has ended, turn left so you are facing the rocks. You want to stand near the edge of the water and angle yourself just slightly to the left of the wall. If you are angled correctly you will jump right past the wall and grab the very edge of the rock face when you roll and jump off of the ledge.
Backwalk and fall into the water then climb onto the platform. Hold L, sidehop, then immediately backflip. You should have landed on the wooden boat without triggering the text. Climb to the bow of the boat, then roll/jump to grab the rock face.
Note: By reading the gossip stone text, the state of the pirate ship interior changes from having the spoils bag to having bombs. If you skip this text, the next time you will enter the pirate ship it will contain the spoils bag. If you obtain the spoils bag and leave, you will be back at the Forsaken Fortress 1 map, and if you watched the Barrel Launching cutscene you will also lose your sword.
If you need to get bombs at all, then reading this text is required.
Simply roll at an angle off of the walkway to the window and perform a sidehop directly after landing to prevent a bump into the wall. From here, you can navigate your way to the searchlight. Also, as a quick way to dispose of the bokoblin, you can lure him towards the ledge and use a quickspin to knock him off of it.
You can achieve the same result as Window Jump by backwalking above a window, and holding up once falling to grab it. It is slightly slower than Window Jump, but it is much easier.
It is important to note that it is completely unnecessary to disable the second and third searchlights in the process of getting to the hero's sword. These are referred to as the "second" and "third" searchlights based on the assumption that you used the above trick to disable the "first" searchlight.
Unless you are right next to them, you will not immediately be caught simply by being in the sight of a moblin. It is possible in most cases to easily escape the moblin's field of vision with good and well-timed rolls to get around corners and over hills quickly.
Instead of simply holding the control stick in the direction you wish to sidle, push the control stick lightly and rapidly. This will allow you to cross the distance a bit faster.
After you have climbed the ladder to the first searchlight, bait the bokoblin into attacking you until you health is reduced to 1/4th heart before killing it. With a deku stick in hand, Then, double target the wall near the ladder to lock Link's angle and move over to the other wall while still holding target to not lose the angle.
Note: While you're hovering, you can still be detected by the two remaining searchlights. Although they cannot catch you mid-hover, they can if you land and heal. This means you have to constantly readjust the height of your hover as to avoid being caught by the searchlights. This hover also only works on normal mode, since there are no hearts in hero mode to heal with.
Jump off of the ledge and at some point once you have cleared the walkway directly below you and Link stops moving forward in his jump do a jumpslash. If you did the jumpslash at the right time Link will either:
In either case, you want to mash B in order to start the hover. This is because, in situation 1, the first slash you take will pull you off of the ledge allowing you to hover OR in situation 2, the recoil from the stick hitting the boat will push you off the ledge allowing you to start the hover. From there, just hover to the hearts that are over the sidle gap.
This trick can be used to defeat the bokoblin at the top of the fortress with the stick you hovered with, which allows you to skip picking up the sword.
If Link doesn't have a sword and goes near a moblin that holds a lantern, then the moblin will act just like he is a guard from Forsaken Fortress 1 and will throw Link into jail. This is because the guards in FF1 and the lantern moblin enemies are actually the same exact enemies, and Link having a sword or not is what determines the moblin's behaviour.
On the overworld, the fastest lantern moblins to access are usually in the Northern Fairy Isle submarine.
It is also possible to lose your sword once you got one by leaving any pirate ship after performing the Gossip Stone text skip, and after obtaining the spoils bag.
Using a bomb roll clip, it is possible to clip out of jail. With the leaf, you can maneuver OoB to escape from jail, without having to crawl. Be careful, as the crawling space can crush Link. Because the wind direction is very bad, it is usually not attempted.
The clip is possible on both sides of the piece of furniture.
Climb the ladder leading to the second searchlight. Once at the top, do a dry roll and turn around. Aim at the post behind the searchlight with the grappling hook and item slide into the corner on your right. If your angle was correct, pressing ZL will shoot Link to the left and he will land under the first sidle gap. From there, you can climb up the ladder and proceed to the top, and you skipped the moblin room.
This trick does not work in the third instance of the Forsaken Fortress (after reading the text with KoRL in TotG after leaving Hyrule 2), because there is an added invisible wall there.
If you don't defeat the bokoblin that guards the first searchlight, then there will be a light preventing you from crossing the second sidle gap. You can however simply item slide across, since item sliding will allow Link to cross the gap in less than a frame, and so he won't ever be in contact with the light.
You can skip the spike raising cutscene by interacting with the bokoblin before the cutscene starts. The easiest and fastest way to do so is by grappling the bokoblin when you don't have the spoils bag, and by throwing a bomb and leafing it when you do have the spoils bag.
It is possible to get inside Forsaken Fortress without needing to blow up the front door and get in on the second visit. Instead, you can swim to the standable spot on the left side of the fortress and item Slide through the corner at that location. From here you can swim underneath the Phantom Ganon trigger to start the battle and be teleported to it, out of the water. This not only skips blowing up the wall, but also the cutscene with the KoRL that would normally play as you enter. If you clip through the wall and go way past Forsaken Fortress, you were likely aiming too far left, if you only go past it a little bit you were likely aiming too far right.
To skip the moblin room, item slide backward into the corner (which is under the first searchlight). With the grappling hook, aim at the middle of the ledge at the other side of the forsaken fortress. Press ZL first, quickly followed by B + up, to grab the ledge at the other side.
If you aim too far left, or if you pressed ZL too late, you might crash your game (happens when Link shoots too far to the left), or you might end up on solid ground before the ledge (happens when Link shoots too far to the right).
After obtaining the skull hammer, there is a series of Item Slides that can be used to quickly get to the top of Forsaken Fortress. The first of these is used to clip through the skull hammer pegs blocking the initial stairs. This slide will only work if you're in third person while sliding so be sure to take out a bomb or the skull hammer before going through the pegs and up the stairs. The second slide is simply up the short ramp to get to the location of the item slide that crosses the entirety of Forsaken Fortress. The 3rd item slide is the moblin room skip above. The next few item slides proceed to climb the next set of stairs and the winding path up to the top door of Forsaken Fortress.
After coming back to Forsaken Fortress from Ganon's Tower, it is fastest to clip out of the island and superswim away from it. To do this you will want to Item Slide (as shown in the video below) to the irregular rock formation on the western side of the island. From here you can clip to the outside with an Item Slide clip where you begin an Item Slide and then hold Up after about a second. If you are not clipping through, or you are clipping through too far, try adjusting your angle to be either more to the right or more to the left than what is seen in the video (this can help if your ESS position for Item Sliding is not perfectly straight).
After you equipped the Skull Hammer, walk up the first two stairs. Stand on the wall facing the ladder on the other side of the area and use your leaf to glide over and grab it.