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.
Ritual. This spell can be cast as a ritual. The ritual version takes 10 minutes longer to cast and expends no spell slot, so it cannot be cast at a higher level; it requires a feature that grants ritual casting.
RollQuest ships the D&D 2014 SRD as a content pack, on a 5e character sheet that does the maths - roll from the sheet and let the numbers work themselves out. Free to start.