This author-artist team do a consistently good job of merging facts in a story framework with John and his dog Pogo as a likeable, credible pair. The content material is never written down, and an amazing amount of solid fact is made interesting to second and third grade readers. Previous books have taught a lot about lumber, trains, wool, gold, paper, and so on. Now comes this surely popular one for small boys who like anything to do with boats as John goes sailing with his father on the lake, and later with Captain Mac in his tug boat. He learns about fog horns and whistles and what the Coast Guard does. He visits the lighthouse keeper and goes to shore in a basket swung on a cable. He learns about boats and buoys and something about sailing as well. One of the best in the series.