The challenge with underwater scenes is lighting it in such a way where it feels accurate without actually being accurate. We didn't want the underwater scene to feel dark or ominous so it was important that my values achieve contrast without skewing the mood of the illustration away from inviting. I developed 2 options, one pushing the blues of the water, the other pushing greens. After some discussion, the blue came out to be the winner.
There was also quite a bit of discussion around the type of underwater vegetation so instead of the eel grass pictured above, we changed it to coral as you see in the final. Here are a few shots to show just how detailed this piece is - but if you're in California and have the opportunity to see the trucks in person, be sure to check them out!