Sea Singer

Your powerful humming carries your music underwater with power.
Prerequisite: At least 1 level in bard.
You can use potent subsonic humming to create bardic performances with auditory components underwater and cast bard spells with verbal components while underwater, even while holding your breath. These spells and effects have the normal range and effect, save that language dependent effects do not function in conjunction with this feat (such as the command spell). You cannot use this feat to cast spells from other classes.
If you are at least level 10, you can cast spells if you magically assume the form of a creature with a swim speed.