The Crafting is relatively simple:
The Diver's Helmet gives you Permanent air underwater
The Diver's Shirt adds more protection underwater
The Diver's Pants allow you to "float" underwater (Basically it's just flying underwater)
The Diver's Boots negate all fall damage if you land in water (Useful for high jumps over 1-block ponds)
Jellyfish would also be added, spawning in ocean biomes and dropping Slimeballs. (Thanks to ninja_master_96 for the idea)
If you could make this, I'd be very grateful.
Edited by Skylar201, 23 November 2011 - 07:35 PM.