Hercules the Harbor Tug

O'Hearn, a nautical photo-journalist and writer, makes his children's book debut with this lively look at the goings-on in a bustling port. Readers accompany two children, Tanika and Noah, aboard the tug Hercules. The amiable captain, Lucy, shows the kids a ferry carrying people and cars; a dredger sucking up mud; tugs pulling a barge and guiding a cruise ship; and a crane unloading a freighter's cargo. Lucy describes each process as well as the Hercules's duties: towing a boom around a newly sunken ship to contain any leaking oil and carrying mail to an anchored tanker waiting for a place to dock. Lucy also explains the function of buoys and lighthouses, points out various marine species (a seal, porpoises, jellyfish, cormorants) and finally steers her craft to join a parade of tugboats. Never mind the questionable likelihood of sighting all this activity in one harbor on a single day-with his crisp prose and concise descriptions, O'Hearn imparts a good deal of information during this short cruise. And although her images of people are not as convincing as those depicting the harbor's hubbub, Lyman's grainy, boldly hued paintings convey the maritime excitement. All ages. (Mar.)