Water Breathing?

This spell grants up to ten willing creatures you can see within range the ability to breathe underwater until the spell ends. Affected creatures grow a small turtle shell on their back for a +1 bonus to AC until the spell ends. Until the spell ends, affected creatures can only breath water through their anus, and thus cannot verbally communicate while under water. Affected creatures also retain their normal mode of respiration.

At Higher Levels: When casting this spell at levels higer than 3rd, the grown turtle shell gets slightly bigger and provides an extra +1 to AC when using a level 6 spell slot, and an extra +2 to AC when using a level 9 spell slot.