The Bends

You assault the internal chemistry of a creature you can see within range, causing bubbles of nitrogen to precipitate in its blood. The creature must make a Constitution saving throw, taking 6d8 poison damage and becoming poisoned for 1 minute on a failure. On a success, a creature takes half as much damage and is not poisoned. If your target is totally submerged in water, in-crease the damage dice from d8s to d10s.

A creature can repeat the saving throw at the end of each of its turns, ending the effect on a success.

At Higher Levels. When you cast this spell using a slot of 4th level or higher, the damage increases by 1d8 for each slot level above 3rd.