First order of business: abilities.
Get rid of Hydration and Ice Body. Neither makes sense for this Pokemon - its not a fucking amphibian or plant, and its body isn't made of ice. I've chosen some possible replacements, backed by dex entries.
>Snow Cloak
-In snow, the pure white coat covering its body obscures it from predators.
>Slush Rush
-Unharmed by even intense cold, it swims powerfully in icy waters.
-It loves frigid seas with ice floes.
-The colder the weather, the more active it becomes.
>Propeller Tail
-It uses its long tail to change swimming direction quickly.
From purely a competitive standpoint, you might consider Refrigerate too. It does get a fair amount of useful normal moves that could benefit: Fake Out, Headbutt, Double Edge are some examples.
For me I'm more of a flavor-over-favor kind of guy and I'm going to give it Snow Cloak and Slush Rush.
Movepool is next.