I presented the client with several options, and he chose the first sketch.
Things were going along quite well, until I started on the little fish. They were so tiny and difficult to work on, and I knew early on that I had to make some changes. Luckily the client was very flexible, and trusted me to make changes as I saw fit.
I wasn't entirely sure how to resolve the situation, so I moved on to the anemone and other under water plants, all of which presented their own set of challenges (weird and clashing colors, too big in some places, too small in others).
I looked at more underwater photos, and finally came up with a solution that got things back on track.
I was very wary of using the bright, neon colors, but I gathered my courage and laid down the first bright stroke. Once I started, I realized how much interest they added to the drawing and I was hooked!
After a total of 12-14 hours, here is the final result. It's a bit more Disney-esque than I planned, but the client was very happy, and the kids really loved it. At the end of the day, that's the most important thing.