Circle of the Sunken (5e Subclass)
From D&D Wiki
Creating Circle of the Sunken
Some say you have a soggy set of skills, however there is much more to water then meets the eyes, just like you.
Beginning at 2nd level, youve spent more time in the water than most people ever will. You ignore the limitation of a swim speed in the druid wild shape column, and gain a swim speed of 30 feet. Additionally you can hold your breath for 2 min + twice your constitution modifier. (Min of two) You also Ignore the properties of underwater combat.
- Sea Exclusives
Beginning at 6th level, You've spent so much time observing wild life underwater, you can enhance what their abilities for your uses. while wild shaped into a creature with a swim speed, you can swim double the normal speed, and become amphibious. Additionally, while underwater you and any of your wild shaped forms gain dark vision.
beginning at 10th level, you become amphibious and are always soaking wet. You gain fire resistance, and have advantage on checks or saves made against others grapple checks. You can no longer wild shape into anything without a swim speed. Additionally you can wild shape into creatures with CR up to half your druid level rounded down.
- Hidden Leviathan
Beginning at 14th level, when you are knocked into death saves and are underwater or are submerged in water before being revived or dying you transform. Your skin changes into a seafoam green, you grow claws, a row of razor sharp teeth, fins on your arms and beck, webbed appendages, and bright yellow serpent like eyes. You gain a bite attack of 4d10 + Strength Mod, And a claw attack of 6d4 + Dexterity. While underwater your Dexterity both increase by +4, you get a double proficiency to stealth checks and saves, and a swim speed of 80. You can only survive above water for 20 seconds before beginning to suffocate. You gain max health, however you can not cast spells, or wild shape. This form lasts for Minutes = to 1+ your Wisdom Mod. While Speaking in this form your voice is distorted and may be hard to understand. When you revert you fall unconscienced again with whatever health you had remaining in Leviathan from. You must finish a long rest to use this feature again.