Add these onto the Parent Race
Ability Scores
Dex +1
Speak with River Beasts
Through sounds, simple gestures, and patterns of bubbles, you can communicate simple ideas with medium or smaller beasts that naturally have a swimming speed.
Swift Swimmer
You gain a swimming speed of 25 feet. In addition, you can hold your breath for a number of minutes equal to twice your Constitution score.
Aquabatics
You have advantage on acrobatics and stealth checks made while submerged.