Books about whales are surfacing almost as fast as you can yell, ``Thar she blows!'' these days. Whales, the Nomads of the Sea, by Helen Roney Sattler, illustrated by Jean Day Zallinger (Lothrop, Lee & Shepard, $14, ages 10 and up), packs a lot of information into an inviting format for middle and older readers. As the book opens, the author is getting acquainted with a pod of gray whales in San Ignacio Lagoon in Baja California. The whales breach, and she follows in her inflatable skiff. They nudge the boat, and she gives them a tentative pat or two. They beat the water with their tails, leaving smooth ``footprints'' on the surface, and she becomes convinced that they, indeed, have come to play.
The opening welcome is carried forward in an engaging text, with chapters titled ``Amazing Mammals'' and ``Sea Soup and Sonar,'' and complemented by soft pencil drawings. After learning about whale talk and the world's biggest babies, readers can dive into an illustrated 60-page glossary of whale species - more than enough to satisfy a demanding science teacher, plenty to fill a rainy afternoon.
Slightly younger readers ought to enjoy Whales, by Gilda Berger, illustrated by Lisa Bonforte (Doubleday, $8.95, ages 8 and up). The large, easy-to-read format and colorful drawings introduce some 20 species of whales, from humpbacks to belugas, and provide some ``awesome'' details. The ``incredible'' and ``tremendous'' blue whale, for example, is the length of three buses, the weight of 25 elephants, and the height of a two-story building. The ``gee whiz'' tone may put parents off, but aspiring cetologists will likely leap for the bait.
A quieter, gently appreciative note is struck in Whale Song, by Tony Johnston, illustrated by Ed Young (G. P. Putnam's Sons, $12.95, ages 4 to 8). Graceful watercolor paintings of mother, baby, grandfather, and uncle whales cavorting ``deep down where seaweed grows and fishes hide'' also introduce number concepts in an intriguing context. As these giants of the deep laugh and sing and eat their lunches, children can count the rippling waves and echoing lullabies.