In recent years, several fine books have been published that are devoted to comprehensive, life–history accounts of single, terrestrial, mammalian species. The major tools for these studies were notebook, binoculars, and keen observation.

The complexity of the sea and the size of some marine mammals present insurmountable obstacles to comprehensive studies. Underwater visibility in the sea is seldom good enough to see from one end of some of the larger whales to the other; obviously, the observational tools in the sea, as in most natural situations, must be complex. However, there is one place where an unusual set of circumstances has reduced the complexities of such studies and provided us with a window into the underwater world. It is one of the most isolated wildernesses on earth: McMurdo Sound, Antarctica. During most of the year, this is the exclusive kingdom of the Weddell seal. Nowhere else, not even in other parts of Antarctica, is it possible to observe and study Weddell seals or any other sea mammal in such detail as here. Yet, paradoxically, the characteristics that make this place so suitable for scientists to observe seals also make it one of the most difficult places for a sea mammal to survive. What we have learned about the Weddell seals in this area seems to justify this contention. The information obtained at times borders on the sensational. By extrapolation, it also has given us new insight into other marine mammals and how extraordinary their life patterns must be.