D O N T breath

Before I say anything, I really do love the technique you're working with here! To me, especially with the color scheme used, it's very relaxing and allows my mind to immediately immerse in water/ocean landscapes...or make reference to the unknown.

*The good aspects of this piece: I really enjoy the colors. Being a big fan with color, I really do like that you don't make the highlights and shadows so dynamic, especially for this particular piece. This gives it a softer radiance, and that's good if you wan to show effortless work.
I like the movement of your strokes in the waves, and again that also helped me recognize it being water material and understand the lighting behind it all.

*The things that you should consider improving: Really be careful with your lighting, ESPECIALLY in liquids. Be especially careful with using black as your shadows, that's a really bold move for an artist. Remember that water is reflective, so try incorporate some movement with the shadows as you did with the highlights (use darker blues/purples too)
The bubbles included appear a bit flat and "random," try to soften out the edges and apply a shadowing so that it could be interpreted as a bubble/reflection of the water.

Overall, you're doing a wonderful job and just keep up the practicing, good luck!! (Btw sorry for the long-a$$ review hahaha)