Dragonbone Cuirass in Mudan Grotto - Morrowind
Location: Mudan Grotto
Requirements: Water Breathing
Video: Location of Dragonbone Cuirass
The Dragonbone Cuirass (or Dragonbone Mail) is found inside of a locked chest in Mudan Grotto; a dungeon southwest of Ebonheart. From Ebonheart you'll need to swim (or use Water Walking) a short distance southwest until you find the island with Mudan Grotto on it, use my map screenshot below for further guidance.
Mudan Grotto's entrance is underwater as is the first part of the dungeon. For this reason in order to safely make it through the first part of this dungeon it's highly recommended that you have a Water Breathing spell. There are a couple of zones to this dungeon - the Dragonbone Cuirass we're after is found in the 'Central Vault' area.
Inside Mudan Grotto you'll need to find a couple of keys (or have high Lockpicking Skill) to make it to the Dragonbone Cuirass in the Central Vault. Below is a step by step of what you'll need to do in order to obtain the Dragonbone Cuirass.
1. Obtain the Dwemer Key to table in Mudan from the corpse in the Right Tower
2. Use the key to open the Rusted Steel Dwemer Table in the main room of Lost Dwemer Checkpoint
3. Enter the Central Vault using the Key to Mudan Dwemer Vault you got in the table
4. Defeat the Steam Guardian inside the Central Vault and loot the Dwemer Guardian Key
5. Open the Steel Dwemer Closet and loot the Dragonbone Cuirass
The hardest thing to find is the Rusted Steel Dwemer Table since it is obscured by the water in the area. Below is a screenshot of my map with me standing right next to the Rusted Steel Dwemer Table, incase you need help finding it.