March has a way of sitting quietly on the calendar, wedged between winter’s last bitterness and the promise of spring. In U.S. Navy submarine history, it does not behave quietly at all. It carries a weight that is out of proportion to its thirty-one days, a month that reaches from the experimental infancy of the submarine force to the violent closing chapters of the Pacific war. When submariners speak of March, they do not do so poetically, but they do so knowingly. Too many boats did not come back. Too many men did not walk down the pier again.