I did this sketch(on the right) wherein my reference photo is the human heart (left side credits). Creating a figure resembling the human heart via different oceanic creatures.

Lineart(left) and then color, shadows, and highlights (right). Done via Ai.

A few finishing touches by adding textures and creating sun beams, bubbles, and adding more shadows to resemble the deep blue. I hope you guys like it! :) 

©kumaoso