Tidal Surge. As an action, you can expend one use of your Channel Divinity to call forth a mighty surge of water energy. Each creature in a 15-foot cone in front of you must make a Dexterity saving throw (DC 8 + your proficiency bonus + your Wisdom modifier) or take 1d8 radiant damage plus 1d8 bludgeoning damage on a failed save, or half as much damage on a successful one. Additionally, on a failed save, creatures are knocked prone and pushed back 10 feet away from you. The damage increases to 2d8 radiant and 2d8 bludgeoning at 11th level and 3d8 radiant and 3d8 bludgeoning at 17th level. Once you use this feature, you can't use it again until you finish a short or long rest.

Watery Resilience. At 6th level, you gain resistance to cold damage. Additionally, you can expend one use of your Channel Divinity to cast the Water Breathing spell.

Tide's Blessing. At 8th level, when you use your Channel Divinity to turn undead, you can choose to infuse the energy with the power of the tides. Undead creatures that fail their saving throw against your Turn Undead feature take an additional 1d8 cold damage. This damage increases to 2d8 at 11th level and 3d8 at 17th level.