Undine Plate 2014
Armor, rare
This bright green plate armor is embossed with images of various marine creatures, such as octopuses and rays. While wearing this armor, you have a swimming speed of 40 feet, and you don't have disadvantage on Dexterity (Stealth) checks while underwater.
Source: Vault of Magic (Kobold Press) · License: OPEN GAME LICENSE Version 1.0a details