US Code
CHAPTER 825— ADMINISTRATION
§ 8221. Chaplains: divine services

(a) An officer in the Chaplain Corps may conduct public worship according to the manner and forms of the church of which he is a member.
(b) The commanders of vessels and naval activities to which chaplains are attached shall cause divine service to be performed on Sunday, whenever the weather and other circumstances allow it to be done; and it is earnestly recommended to all officers, seamen, and others in the naval service diligently to attend at every performance of the worship of Almighty God.
(c) All persons in the Navy and in the Marine Corps are enjoined to behave themselves in a reverent and becoming manner during divine service.