Come join the fun as students take a submarine bus on a field trip to explore the ocean deep, in this wordless picture book from the creator of Field Trip to the Moon!Students dressed in deep sea helmets travel to the ocean deep in a yellow school-bus submarine. When they get there, they frolic with fish, chase luminescent squid, and discover an old shipwreck. But when it's time to return to the submarine bus, one student lingers to take a photo of a treasure chest and falls