This part will get you through the entire Ocean Temple.
Inside the Temple
There's nothing we need to get outside the temple, so let's proceed inside.
In the first room you enter there are pots to break for hearts if you need them. There are also posts to your left and right in this room, but we'll need to get a certain something from this temple first in order to use them. Proceed to the hallway to the north. At your right you will see a hallway with boulders dropping down from the northernmost end rolling down to the southernmost end. We can't go that way yet. Instead, go to the room on your left, using the Boomerang to stun the Electric Chuchus before you slay them. In them are four stone tablets, telling you the order of what you'll need to do directly one floor above. Make a note of that order on your map. Then go through the door at the upper left corner of that room and head east, staying as south as possible to avoid the arrow launchers. Then go north and head for the staircase to take you to Floor 2.
There's a crack in the wall to the left of where you entered this floor, but there are no Bomb Flowers nearby to blow it up. Ignore that unless you want to come back later to explore. Instead, go south and get onto the moving platform riding it to the west, protecting yourself from the arrow launchers. Then go south to another moving platform that will take you southeast. In that room there are four switch orbs you need to hit with the Boomerang. In the same order that was shown to you by the stone tablets one floor below, hit all four switch orbs. (The order is west, east, north, south.) A door will open in the southeast where the moving block takes you. Go through that door and, using the Boomerang, hit the switch orb that's in the hallway north of you to close up one trap door and open up another for the rolling boulders. Then go back across the moving platforms to the staircase and head down to Floor 1 again.
When you get to the hallway that's north of the first room you entered the temple in, the rolling boulders in the hallway to your right are only dropping from halfway down the hall now. Time your way past them to get to the short passageway on your right into a room where you see a thorned arch blocking a small passageway near the east. Ignore that and go north toward a staircase that will take you back to Floor 2.
Go south into a room where there's two Electric Chuchus to stun and slay, then go to the passageway on your east to a staircase heading to Floor 3.
Go west from the room you've just entered this floor in, and you'll enter a closed-door battle with the Snapper, a thug with a whip. He will grab Link with the whip and pull him this way and that. Let the Snapper pull you toward him so you can give him some strikes with your sword. Defeat him and all four doors of the room will open, and a treasure chest will appear to give us our next useful item -- the Whip. To use it as a weapon, just simply tap the stylus in the direction you want to whip it in. It also has another use that will come in handy very soon in this temple.
Let's proceed to the room that's to the west. As you go through the door, you'll see a post like the ones you saw near the entrance of the temple. Here's where Link becomes the Indiana Jones of New Hyrule: with the Whip, strike the post so that you can swing across to the other side. Then head for the staircase in the upper left corner to go up to Floor 4.
In the room that you enter there's a stone tablet to your right that reads: "Three handles sit before you. Pull only the one farthest from your grasp." This is an important clue for what's coming up.
Now head to the right and then south to another post on your left. Use the Whip to swing across the gap here, then head south and to the right into a room with some Electric Chuchus in it. Give them a good whip to stun them before striking them with the sword. Then head for a fish mouth that has a handle sticking out of it on your right. Latch onto the handle with the whip to pull it out, and it will open a door to your left. Go through the door to the north and you'll see three narrow passageways leading to three fish mouths, each with handles sticking out of their mouths. Remember the clue from the other room and pull out the handle in the mouth that's farthest from your grasp (which is the one on the right). This will cause a bridge to appear crossing a gap to the south. (If you pull the handle on the left, you'll cause a rolling boulder to fall on you, and if you pull the one in the middle, then you'll launch arrows at yourself.) Cross the bridge and head for the staircase on your right that will take you back down to Floor 3.
Go all the way to the left and you'll see two fish mouths, with the one on the left having a handle sticking out. Use the Whip to pull the handle out, revealing a sword, and aim it so it goes into the right fish's mouth. A chest will appear to your left, and a post will appear to your right to let you whip-swing into the center room. Open the chest to get a small key, then whip-swing into the center room so you can whip-swing into the north room. Go to your left, slaying the Electric Chuchus there, then open the locked door to go up the stairs back to Floor 4.
Pull the handle in the fish mouth on your left with the whip to open the door that's south of you, then go to the right. Here we have three posts we'll need to whip-swing in succession: when you swing past one post, instantly strike the other. Then go south into a closed-door battle with some Helmet Chuchus. Whip the helmets they wear off their heads before striking them down. The closed door will reopen, and a door to the right of that will now open. Go through that door and up the stairs into Floor 5.
To the left from where you entered this floor, you'll see a row of fish mouths, some with handles in them and some without. In fact, as you explore this floor (which has two Snappers in the center area you'll need to deal with), you'll see four rows of fish mouths like this. For now, head for the narrow passageway from the center area that's going to your left and head all the way west until you come across a mouth with a handle in the corner. Pull on that handle, and it will release a propeller you can latch onto with your Whip. Let the propeller carry you across the chasm to the southwest section of this floor where you can get off, and there's a staircase that will take you to Floor 6.
In the first room you enter Floor 6 in, you'll have a closed-door battle with some blue Electric Chuchus, except that your weapons don't have any affect on them. Fortunately, there's a fish mouth in that room that you can pull swords out of. Pull them out and whip them at the Electric Chuchus to slay them. The closed door will reopen, and a post for whip-swinging will appear on the far east of this floor. Since this room is a dead-end, go back the same way you came to Floor 5.
Use a propeller to travel back to the narrow passageway on the west side of this floor, then pull the swords out of the three fish mouths near the passageway. This will cause four posts to appear on the north end of this floor to let you whip-swing your way to the staircase in the northwest section of this floor. Go over to the northeast section where there's a thorny arch blocking your way to the posts and use the Whip to pull the thorns out of your way. Then whip-swing to the staircase that will take you to Floor 6.
Go over to the five posts on your right and whip-swing your way to the northeast section of this room. Strike the switch orb, and you'll cause one of the posts you've used to reappear. (Huh?) Head south and to the left where you'll see another row of fish mouths, some with swords and some without, and near the center is a stone tablet that reads: "Remember the placement of the blades. That knowledge will be useful in another similar room." So let's explore this floor. It also has four rows of fish mouths like the ones on Floor 5, except that the placement of the swords in the mouths is different. Just make a note of which fishes have swords in them and which fishes don't. Then go down the narrow passageway on the east side of this floor all the way to the right and whip-swing your way to the north where there's a chest with a small key in it. Then go back to the five posts and whip-swing your way to the staircase heading back to Floor 5.
After you've whip-swinged your way back to where you have access to all four rows of fish mouths, use your knowledge of the placements of the swords in the fish mouths on Floor 6 and rearrange the ones on this floor accordingly. This will open up a door in the southeast corner that's past a whip-swinging post and below a staircase. Head for the locked door at the south end to open it and then whip-swing your way to the staircase heading back to Floor 6.
Use a propeller to hover your way onto a moving platform moving in a circle near a stationary platform on the south end of this floor, where lies the Big Key. Press the floor button next to it, and a bridge crossing a gap to the north will appear. Now comes the tricky part: as soon as you cross the gap with the Big Key, Key Masters will appear to flick Link away and to grab the Big Key and place it back in its home spot. Try to get the Key Masters out of your way first before you attempt to bring the Big Key to the Big Key door at the top of the stairs to unlock it. Go past the door to the stairs to take you to Floor 7.
There's nothing we really need to get on this floor, just pots for breaking to get hearts and a blue portal to take you to the entrance of the temple. Whip-swing across to the right and head for the door to take you to meet the Temple Boss.
Temple Boss: Phytops
When you first enter the chamber of the boss, you'll have to do some swinging across posts first to get to it. Whip-swinging your way to the first two ledges won't be a problem. However, when you get to the second ledge, there's a thorny tentacle in your way of swinging across to the next ledge. Also you'll be dripped on by some pink goo that will do heart (meter) damage. Use your Whip to rip off a thorn from the tentacle and aim it at the tentacle's eye, making it disappear. Whip-swing over to the next ledge, and you'll have another tentacle to take out the same way. On the last ledge, there's some pots to break to restore hearts. Activate a propeller that you can ride on to get to the top. There you will see a hideous plant creature called Phytops, who is the temple's boss.
Phytops will stick out its thorny tentacles to keep you confined within a limited area while dripping more of its pink goo on you. Use the Whip to rip off a thorn and then aim it at the creature's head. Do it again and you'll expose the eye. Now rip off a thorn and aim it at Phytops' eye. It will loll over to the side, close enough for you to strike its eye with the sword. It will dive back into the water to cover its eye again, and then stick out two more tentacles to whip at you with. Avoid getting hit by them. Repeat the same strategy of ripping off thorns and aiming them at Phytos' head to expose the eye so you can hit the eye with a thorn and then strike at it with the sword. After two successful strikes, the creature will have the two other tentacles remain visible to strike you with. Avoid them while continuing to repeat the same strategy two more times. Eventually Phytos will decay and turn to dust. A Force Gem statue will appear, and so will a treasure chest that contains your next Heart Container.
You've completed the Ocean Temple. Now step into the blue portal to return to the entrance.