Crashing Waves

You hold aloft your stone, causing ice-cold waves to crash and roil around you. Creatures in a 5-foot-radius of you must make a Dex- terity saving throw. On a failed saving throw, the creatures suffer 2d8 cold damage, and gain vulnerability to damage dealt by this spell until the end of your next turn. On a successful saving throw, the creatures suffer half damage, but no further effects.
On each of your subsequent turns, you may cause waves to crash around you as an action. Creatures within 5 feet of you must make a Dexterity saving throw. On a failed saving throw, creatures suffer 1d6 bludgeoning damage, and gain vulnerability to damage from this spell until the end of your next turn. On a successful saving throw, the creatures suffer half damage and no further effect.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the cold damage increases by 1d8 and the bludgeoning damage increases by 1d6 for each slot level above 2nd.