Gift of The Kelp (Tier One)

Passive: Your lung capacity and swimming speed permanently increase, allowing you to swim with an extra 10 ft. of movement speed and hold your breath for an additional five minutes.

Active: You can magically summon a kelp tendril that strikes at your foes. As a bonus action, you create a 10-foot-long tendril at a point you can see within 60 feet of you. The tendril lasts for 1 minute. When you create the tendril, you can make an attack roll using double your proficiency bonus to hit against one creature within 10 feet of it. On a hit, the target takes a number of d8 equal to half your proficiency bonus rounded up of cold damage, and its speed is reduced by 10 feet until the start of your next turn. As a bonus action on your turn, you can move the tendril up to 30 feet and repeat the attack.