Mariner's Plate Armor

Magic Armor (plate armor), Uncommon

Description:

While wearing this armor, you have a swimming speed equal to your walking speed. In addition, whenever you start your turn underwater with 0 hit points, the armor causes you to rise 60 feet toward the surface. The armor is decorated with fish and shell motifs.

Source: Dungeon Master’s Guide, page 181

Bio:

Mariner's Plate Armor

Tyranny of Dragons RaoGung