Final Fantasy VII
Disc 2: Junon Underwater Reactor
Pack up your guys and head to Junon. Talk to everyone in the lower town. Betcha didn’t know you were engaged, did yah? Heh heh.
Talk to the guard at the bottom of the elevator to go up to the top and guess what? NEW MUSIC!!! Heh heh.
You can talk to the guards who don’t know how to keep their mouths shut if you go onto the airport exit, the door that leads right. You can also get back into the locker room by going through the door that leads up. Neither one is really important.
As you run down the main road, you’ll get a different view for a second as Cloud says, “I may be mistaken, but… Doesn’t it feel like we’re missing something?” You can probably see from the angle there that a very large Junon Cannon is no longer there. So don’t freak out. You haven’t forgotten something.
Anyway, there’s nothing really useful in the city that you don’t already have, so run toward the other side of town. When you go under the elevator, and hear the obnoxious whistle, head toward the bottom of the screen and left. The door at the end of the hallway leads to the undersea reactor. On the way, you’ll see Larry, Moe, and Curly’s special forces strike team. Kidding. Sort of.
Look for the door leading up near the end of the hallway and you should be able to find it. At the bottom of the elevator, ignore the dog for now. We’ll get to him later. Head down the path. If you see red buttons along the way, you’ll probably want to ignore them.
Go down a few more hallways to a freight elevator, and take that down to the bottom. On the next screen, run toward the top of the screen, and you should now be on a screen with an underwater glass tunnel, looking at the animals swimming around.
Hey look, it’s Mr. Dolphin! “Hi Mr. Dolphin!”
The Ghost Ship enemy in this area is the only source for the Miscellaneous ItemsTrade to guy in Kalm for Underwater Materia, which can be traded in Kalm for the Underwater Materia. Equip one or more Enemy Lure Materia and wander around. Once you’ve fought one of these guys once and morphed it, you can swap out the Enemy Lure Materia. Ghost Ship enemies have 6,600 HP and 100 MP, and are weak against Holy. Attack to get the HP down, use Magic Hammer to eliminate its MP, and then use Morph to get the Miscellaneous ItemsTrade to guy in Kalm for Underwater Materia. If you have Mime Materia, all the better.
Head down the path until you get to the room with the three cylinders at the top of the screen. It’s an elevator. NOW you can press the shiny red button. When you get to the bottom, exit the elevator and head left along the path.
Save and/or Restoration ItemsTarget: All, Restores ALL HP/MP at save point or on world map if you want, then head up and right. “Talk” to the first group of soldiers, then continue right.
Keep going and you’ll eventually watch the Key ItemsKey Item: You can collect all four! (And when you do, take them to Bugenhagen's Observator and up the elevator to get Bahamut Zero) get taken by crane toward the submarine. Run right to try and stop it, then go forward and talk to Reno.
Boss: Carry Armor
Strategy for fighting Carry Armor, Left Arm, and Right Arm: There is nothing to steal from these enemies. Carry Armor has 24,000 HP and 200 MP. The left and right arms have 10,000 HP and 100 MP each.
They are all weak against Lightning, so fire up your Enemy Skill Trine. It should do about 2k damage to each of them. That plus some Mime and Slash-All should make fairly quick work of him. Big Guard is also useful, but don’t bother with Demi.
If you have Mime Materia, don’t forget that miming an attack doesn’t require MP. Consider linking Quadra Magic Materia to Lightning Materia. A character could cast 4x Lighting 3, which could be mimed by one or more other characters. You can do that with Quake also.
This battle certainly helped level up my materia, too. I received a Tifa's WeaponsTifa's Weapon. Attack: 86; Attack %: 255; Connected Slots: 4; Unconnected Slots: 0 from this battle.
After the battle, head left and open the box there for the Cait Sith's WeaponsCait Sith's Weapon. Attack: 95; Attack %: 95; Connected Slots: 6; Unconnected Slots: 0. Now run toward that submarine at the far end of the screen.
There are two more boxes en route, though. The first one has a Cid's WeaponsCid's Weapon. Attack: 86; Attack %: 102; Connected Slots: 2; Unconnected Slots: 0; Growth: Tripple, Cid’s triple-growth weapon. The other box contains the Key ItemsKey Item: Use in Da Chao to get past large flames., which suppress the flames that prevented you from reaching the back of the cave on Wutai’s Da Chao statue. When this section is over, be sure to check it out.
Now that you have all four things you needed from here, head toward that submarine. After a few battles, you should be good to go. Enter the sub, fight the Both Sides Attack, and then save/Restoration ItemsTarget: All, Restores ALL HP/MP at save point or on world map if you want. Head inside the cabin.
Submarine Mission
Take the guys there prisoner, then head to the top of the screen and examine the captain’s chair. Read the manual if you haven’t done this before, then start the mission. Read the instructions. It’s easier than me trying to explain it, but I will say this: I beat this mission in about 30 seconds.
However long it takes you, don’t forget to pilot your sub to the wreckage of the red sub on the ocean floor, wherever you sink it. That’s how you get the Red Key ItemsKey Item: You can collect all four! (And when you do, take them to Bugenhagen's Observator and up the elevator to get Bahamut Zero).
After obtaining the Key ItemsKey Item: You can collect all four! (And when you do, take them to Bugenhagen's Observator and up the elevator to get Bahamut Zero) from the wreckage, surface with X and head to the dock at Junon Harbor. I would take this opportunity to save.
Cloud implies that you MUST get to Junon Harbor NOW or everything will fail. This is not actually the case. I would suggest completing a few optional tasks before heading there:
Optional: Wutai and Leviathan Scales
Once you have retrieved the Key ItemsKey Item: Use in Da Chao to get past large flames. from the underwater reactor, head to Wutai and climb the mountain with the Da Chao statues. Use the Select button to see all the exits you can take. Take the first right, then the U-turn. At the Tee crossing, go right, then go up, and then enter the cave.
Inside is the Cid's WeaponsCid's Weapon. Attack: 66; Attack %: 100; Connected Slots: 0; Unconnected Slots: 8, if you don’t have it already. Approach the fire and it will die down now that you have the Key ItemsKey Item: Use in Da Chao to get past large flames.. The first fire pit has Yuffie’s weapon Yuffie's WeaponsYuffie's Weapon. Attack: 90; Attack %: 116; Connected Slots: 4; Unconnected Slots: 4 inside. You may have to approach it twice. The second has Steal as Well Materia.
Optional: Kalm, Guide Book, and Underwater Materia
When you finish the Wutai Key ItemsKey Item: Use in Da Chao to get past large flames. section above, hop back on the Highwind and head to Kalm. The house on the far-right lower corner of the screen has a funny old guy upstairs. He wants three things: the Miscellaneous ItemsTrade to guy in Kalm for Underwater Materia, Miscellaneous ItemsTrade to guy in Kalm for a Gold Chocobo, and Miscellaneous ItemsTrade to guy in Kalm for Master level Magic, Summon and Command Materia.
Now that you have one of them, go talk to him and you can get the Underwater Materia. Equipping this when you fight Emerald Weapon (See the Beating Weapon Section) will remove the battle’s time limit. While it’s possible to beat Emerald Weapon without this, it is significantly more difficult.
Optional: Find the Gelnika
Before returning to Junon Harbor, consider visiting the Sunken Gelnika. This is where you get Yuffie’s Yuffie's WeaponsYuffie's Weapon. Attack: 96; Attack %: 112; Connected Slots: 8; Unconnected Slots: 0; Growth: NO GROWTH! weapon and unlock the best stat-source farming spot in the game. I would get the weapon now, but hold off on the serious grinding until after the Rocket Town Huge Materia section, when you can also work toward Master Summon Materia. See the Sunken Gelnika section for the route, loot, enemy tables, and morphing setup.