LETHAL TIDES

In war, sometimes the most important weapons are information and expertise, as this biography of a remarkable woman demonstrates.

Musemeche, a veteran pediatric surgeon, recounts the career of Mary Sears (1905-1997), who advanced the science of oceanography while making critical contributions to the war effort. Originally a marine biologist specializing in plankton, after Pearl Harbor, she was sent to the Oceanographic Unit at the Hydrographic Office of the Navy. Though she was meant to be a “placeholder for a man” who had enlisted, her abilities soon became apparent. One of her first projects dealt with studying undersea temperatures, which were especially significant for submarines. As she gathered a (mostly female) team around her, the focus shifted to providing maps for amphibious assaults on Japanese-held islands. The near-disastrous landing on Tarawa had underlined the need for better intelligence, especially about hazards like tides, reefs, waves, and weather. Sometimes, information was available in archives and had to be painstakingly excavated. Ironically, Japanese fishing surveys often turned out to be useful, but otherwise, charts had to be developed from observations of a target. Musemeche notes that Sears had a talent for sifting through huge amounts of raw information to find the important parts. In an era when female scientists had to battle for credibility, the value of her work was quickly recognized, to the point that keeping up with the demand for data and information was a constant strain. There is no telling how many lives were saved due to her work, but Adm. Chester Nimitz, for one, said that the material from Sears’ unit was essential. No doubt the men on the front lines would have agreed. Musemeche tells the story with a sense of restraint that fits the subject, and she notes that a few years after Sears died, the Navy named a new oceanographic survey ship the USNS Mary Sears—a fitting tribute to someone who made a difference.

Overdue acknowledgment of an important figure in American military history.