Division Officer's Guide, 12th edition, is a handbook for junior officers and petty officers of the U.S. Navy and U.S. Coast Guard afloat, in the air, under the sea, and ashore. Originally written in 1952 by Capt. John V. Noel Jr., and last revised in 2004, the book provides division officers with basic lessons of leadership, organization, administration, training, and discipline. This volume has evolved with our rapidly changing world. Terrorism has become an international security issue, men and women now serve together superbly in all our ships at sea, and technology continues to change virtually every aspect of naval operations. Despite the technological advances in the tools available to leaders, a great constant remains--the direct personal impact that the division officer has on sailors each day. A division officer's fundamental task is to build the core elements of a winning team. Division Officer's Guide, 12th edition, is written to reinforce the skills and competencies at the heart of this charge.