Winter's Zone of Frost

Developed by Winifred "Winter" Teresal as she traveled with the pirate crew of the "Something Wicked". Their many underwater adventures led her to need a spell that did not do fire damage, so she quickly got to work on a way to still be useful to the crew while they were raiding shipwrecks, sahuagin lairs, and other various underwater caves. 

A small orb of ice releases from your hands to a point you choose within range and then explodes into a circular zone of icy wind and hail. Each creature in a 20-foot-radius sphere centered on that point must make a Dexterity saving throw. A target takes 6d6 cold damage on a failed save, or half as much damage on a successful one.

The zone of frost causes the entire area of effect to become difficult terrain until the end of your next turn

At Higher Levels. When you cast this spell using a spell slot of 4th level or higher, the damage increases by 1d6 for each slot level above 3rd.