Andrew Lost in the Deep — J.C. Greenburg

Andrew, Judy, and Thudd drive the Water Bug deep into the ocean, where the only light comes from strange glowing creatures. Just as they're passing over the deepest place on earth, the trusty Water Bug loses power! Now instead of saving the giant squids, Andrew, Judy, and Thudd will have to save themselves - or be lost on the bottom of the ocean forever!