Water Descender (3.5e Invocation)
From D&D Wiki
You can use this invocation to adapt with submersion in water. Gain ability to breathe water as well as air, and also gain +10 to listen while submerged in water. You are immune to nonlethal damage while submerged in water. While this invocation is in effect, you have a -2 penalty to Dexterity on land. This effect lasts for an hour per caster level, or until you wish to end it (ending it is a swift action).