Here's the sketch.
And some details. I started by adding two different colors of watercolors to my background. I fussy cut fish from a paper from Bella Blvd's Secrets of the Sea collection from a few years ago.
I looked through my dies to see if I could find some that looked like seaweed. I found these Tim Holtz Thinlets. First, I watercolored some paper, and after it dried, I die cut the leaves and made it so that some of the fish were swimming through the fronds.
I love the awesome Florence alphas by Blvd. I added a heart, like I always do when I'm giving away my pages.
I added some fish bubbles with pen and then added some "water drops" in the form of clear Nuvo Drops.