(a) Each person assigned duty as officer in charge of a navigational or engineering watch, or duty as a rating forming part of a navigational or engineering watch, on board any vessel that operates beyond the Boundary Line shall receive a minimum of 10 hours of rest in any 24-hour period.
(b) The hours of rest required under paragraph (a) of this section may be divided into no more than two periods, of which one must be at least 6 hours in length.
(c) The requirements of paragraphs (a) and (b) of this section need not be maintained in the case of an emergency or drill or in other overriding operational conditions.
(d) The minimum period of 10 hours of rest required under paragraph (a) of this section may be reduced to not less than 6 consecutive hours as long as—
(1) No reduction extends beyond 2 days; and
(2) Not less than 70 hours of rest are provided each 7-day period.
(e) The minimum period of rest required under paragraph (a) of this section may not be devoted to watchkeeping or other duties.
(f) Watchkeeping personnel remain subject to the work-hour limits in 46 U.S.C. 8104 and to the conditions when crew members may be required to work.
(g) The Master shall post watch schedules where they are easily accessible. They must cover each affected member of the crew and must take into account the rest requirements of this section as well as port rotations and changes in the vessel's itinerary.