SRD:Plate Armor of the Deep

Plate Armor of the Deep: This +1 full plate is decorated with a wave and fish motif. The wearer of plate armor of the deep is treated as unarmored for purposes of Swim checks. The wearer can breathe underwater and can converse with any creature with a language that breathes water.

Moderate abjuration; CL 11th; Craft Magic Arms and Armor, freedom of movement, water breathing, tongues; Price 24,650 gp; Cost 17,150 gp + 600 XP.