The Secretary may, whenever the needs of the service require, but not more often than annually, convene a board consisting of not less than six officers of the grade of rear admiral (lower half) or rear admiral to recommend for continuation on active duty officers on the active duty promotion list serving in the grade of captain, who during the promotion year in which the board meets will complete at least three years’ service in that grade and who have not been selected for promotion to the grade of rear admiral (lower half). Officers who are subject to retirement under section 2149 of this title during the promotion year in which the board meets shall not be considered by this board.

Whenever he convenes a board under this section, the Secretary shall establish a continuation zone. The zone shall consist of the most senior captains eligible for consideration for continuation on active duty who have not previously been placed in a continuation zone under this section. The Secretary shall, based upon the needs of the service, prescribe the number of captains to be included in the zone.

Based on the needs of the service the Secretary shall furnish the board with the number of officers that may be recommended for continuation on active duty. This number shall be no less than 50 percent of the number considered. The board shall select from the designated continuation zone, in the number directed by the Secretary, those officers who are, in the opinion of the board, best qualified for continuation on active duty.

The provisions of sections 2108, 2109, 2115, and 2117 of this title relating to selection for promotion shall, to the extent that they are not inconsistent with the provisions of this section, apply to boards convened under this section.

The Secretary shall prescribe by regulation the detailed procedures whereby officers in a continuation zone will be selected for continuation on active duty.

A board convened under this section shall submit its report to the Secretary. If the board has acted contrary to law or regulation, the Secretary may return the report for proceedings in revision and resubmission to the Secretary. After his final review the Secretary shall submit the report of the board to the President for his approval. Except as required by the procedures of this section, the proceedings of the board shall not be disclosed to any individual who is not a member of the board.

Each officer who is considered but not recommended for continuation on active duty under the provisions of this section shall, unless retired under some other provision of law, be retired on June 30 of the promotion year in which the report of the continuation board convened under this section is approved, or the last day of the month in which he completes twenty years of active service, whichever is later.

Notwithstanding subsection (g) and section 2149 of this title, the Commandant may by annual action retain on active duty from promotion year to promotion year any officer who would otherwise be retired under subsection (g) or section 2149 of this title. An officer so retained, unless retired under some other provision of law, shall be retired on June 30 of that promotion year in which no action is taken to further retain the officer under this subsection.