Water Breathing

3rd-Level Transmutation (Ritual)
Casting Time: 1 action
Range: 30 feet
Components: VSM (a short reed or piece of straw)
Duration: 24 hours

This spell grants up to ten willing creatures you can see within range the ability to breathe underwater until the spell ends. Affected creatures also retain their normal mode of respiration.
At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, you can target three additional creatures for each spell slot above 3rd.

Source: PHB 287, SRD