Final Fantasy III: Aquatic Caves

This is a small hack that overwrites the data of an unused Battlefield in the ROM to create an "Aquatic Cave" background where you can learn the "Water Rondo" dance. It has the same color palette as the caves in the Serpent Trench. The logical places to put this were in the cave between Figaro Castle and the Ancient Castle, since the Serpent Trench music plays there, and Hidon's Cave, which rises from the ocean.

Title: Aquatic Caves Patch
Author: PowerPanda
Version: 2.0
Applies to: FF3us v1.0 (headered)

Contents: aquatic caves.ips
aquatic caves removal.ips
(Run the removal patch to back out the changes)

--------------------------------------------------------------------------------
-=Intro and Description=-
I first played Final Fantasy III before the internet was a daily thing, and nobody
that I knew had a strategy guide for it. So, like any sane person, I never thought:
A. That the world would be destroyed,
B. That some locations would become inaccessible, and
C. That I should take Mog on the ridiculously long sidequest through the Serpent
Trench so that he could get a Dance that wouldn't be available later.
Cut to 1 month later, when I was trying to complete the game. I had taken Mog to
every location, and still couldn't figure out how to get the last Dance. When I
found out, via the internet in the school's computer lab, that Squaresoft had not
thought to include a place to unlock it in the World of Ruin, I felt betrayed.

This patch was created to soothe the pains of my 13-year-old self. It overwrites
the data of an unused Battlefield in the ROM to create an "Aquatic Cave" background
where you can learn the "Water Rondo" dance. It has the same color palette as the
caves in the Serpent Trench. The logical place to put this was in the cave between
Figaro Castle and the Ancient Castle, since the Serpent Trench music plays there.
Think of it as a submerged cave that was drained of water when the world was
destroyed.

As of version 2.0, Hidon's Cave (aka Ebot's Rock) has also been added as a location
where Water Rondo can be learned. It has the same palette changes.

--------------------------------------------------------------------------------
Code Changes

==Creating the "Aquatic Cave" Battlefield==
E7/0126: 91 FF 09 (Set Battlefield $31 Tileset to Cave)
03 03 02 (Use Arrangement 3, Palette 2 - WoB Cave)

ED/8E8C: 05 (Set "Water Rondo" as the dance for Battlefield $31 - Aquatic Cave)

==Changing the Ancient Cave===
ED/C2B3: B1 (Change Ancient Cave 1 Battlefield to $31 - Aquatic Cave)
ED/C2CA: 15 (Change Ancient Cave 1 Palette to $15 - WoB Cave)
ED/C2EB: 15 (Change Ancient Cave 2 Palette to $15 - WoB Cave)

==Changing Hidon's Cave===
ED/C316: B1 (Change Hidon's Cave Battlefield to $31 - Aquatic Cave)
ED/C32D: 15 (Change Hidon's Cave 1 Palette to $15 - WoB Cave)
ED/C337: B1 (Change Hidon's Cave Battlefield to $31 - Aquatic Cave)
ED/C34E: 15 (Change Hidon's Cave 2 Palette to $15 - WoB Cave)

No-Intro Name: Final Fantasy III (USA)
(No-Intro version 20130701-030720)
File SHA-1: 258BCBC5B7BCC25098BF598C4FF2AA6AC00FDE16
ROM SHA-1: 4F37E4274AC3B2EA1BEDB08AA149D8