Bonesand Call

You channel magic from the depths of the sea to summon forth a burst of rocky sand in a 15-ft cone originating from yourself along side 1d4 bonesharks. All creatures within the cone that are not bonesharks must make a Constitution saving throw (with disadvantage if underwater), taking 1d6 bludgeoning damage plus 1d6 slashing damage and be blinded for 1 minute on a failed save, or half as much damage and not be blinded on a success.  The bonesharks are under your control for the duration as long as you maintain concentration, act on your initiative, and await your orders. Given no orders, they attempt to bite anything within reach. 

If you lose concentration or the duration ends, the bonesharks are freed from your control and do not attack you after being freed. After 1 minute has passed, they disperse into magical energy and return whence they came in a small burst of sand.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, the amount of bonesharks summoned increases by 1d4 and the area of the sand-cone increases by 5 ft for each slot level above 2nd.