Airen's Steam Geyser

while palms facing each other point the direction you want to cast the spell, a sudden burst of steam shoots in a line of 50 feet long and 5 feet wide in a direction you choose. Each creature in the line must make a Dexterity saving throw. A creature takes 4d8 force damage, and 4d8 fire damage on a failed save, or half as much damage on a successful one.

When the spell cast in water any creature that fails the saving throw suffers additional 1d8 (maximum 10d8) force damage and knocked 15 feet back.

At Higher Levels. When you cast this spell using a spell slot of 5th level or higher, the damage increases by 1d8 (for each damage type) for each slot level above 4th.