This bluish metal armor seems oddly light in your hands, with a liquid sheen.
This armor is buoyant in water or similar liquids. Armor that has this property does not apply an armor check penalty on your Swim checks. Additionally, it grants you a +2 competence bonus on Swim checks while you wear it.
Prerequisites: Craft Magic Arms and Armor, swim.
Cost to Create: 2,000 gp, 160 XP, 4 days.
Source: Magic Item Compendium, page 9. An earlier property of the same name but with somewhat different abilities appeared in Stormwrack.