How a hobby came into being, how it grew and what it led to since the author, whose name is familiar to many, experimented since boyhood with underwater observation. It's a very specialized sort of thing, with a touch of the amateur in approach, but here and there you will find someone who will want to know how undersea diving and photography has been done -- and can be done since one section is a guide for others to go and do likewise. Diving helmets, photography -- motion picture and still -- , experiences above and below water in the Bahamas, etc. make up the substance of the book. Very conjectural sporting book sale.