Like frames from an animated sci-fi cartoon, the undersea pictures in salmon and blue project not something real but a fantasy world. And the text reinforces that notion in parts: there are fish -- ""Most of them are friendly"" -- but ""If you go after the octopus, he'll squirt out a blob of ink."" With characteristically poor discretion, what is taken 'seriously' -- the workings of the old diving bell and the air hose (the only pre-scuba tools cited) -- could have been omitted altogether for the purposes of a third-grade introduction. As presented, however, via diagrammed home-experiment analogies, the exposition is wholly confounding -- nowhere indicating how the rise and rest of an air bubble inside a submerged glass is related to the operation of the air hose. . . for instance. At best suggestive instead of demonstrative, the best suggestion being that the realm of the aquanauts might be a nice place to visit (if you take a friend ""so that you can help each other"").