Deep Darkvision

When underwater you can see in dim light within 120 feet of you as if it were bright light and in darkness as if it were dim light. You discern colors in that darkness only as shades of gray.

Tidal Breath

You have draconic breath that pulls from torrential arcana of the sea. You can use your action to exhale a torrent of frigid sea water in a powerful crushing blow. In a 30ft line each creature in that area must make a Dexterity saving throw (DC = 8 + your Constitution modifier + your proficiency bonus). A creature takes 1d6 damage cold and 1d6 bludgeoning damage on a failed save, and half as much damage on a successful one. The damages increases to 2d6 at 6th level, 3d6 at 11th level, and 4d6 at 16th level. After you use your tidal breath, you can’t use it again until you complete a short or long rest.

Frigid Resistance

You have resistance to cold damage.

Frigid Warding

Starting at 5th level, as an action, you can channel your draconic energy to protect yourself. For 1 minute, you have resistance to fire damage and become immune to cold damage. Once you use this trait, you can’t do so again until you finish a long rest.

Aquatic Movement

You can swim at quick quicker paces when at sea. As a bonus action you may use the Dash action to double your swimming speed.