References on Working Hours
Prepared  7/12/2004 by Captain Greiner

Marine Safety Manual Vol III, Chapter 20

 H. Workhour Limits.

1. Tankers.

The Oil Pollution Act of 1990 (OPA 90) amended 46 U.S.C. 8104 by adding a new subsection (n) which reads as follows: "On a tanker, a licensed individual or seaman may not be permitted to work more than 15 hours in any 24 hour period, or more than 36 hours in any 72-hour period, except in an emergency or a drill. In this subsection, "work" includes any administrative duties associated with the vessel whether performed on board the vessel or onshore."

2. Other Vessels.

Various sections of 46 U.S.C. 8104 limit the number of hours that licensed individuals and/or crewmembers may be required to work on certain classes of vessels. This does not preclude seamen from voluntarily working beyond those limits and possibly becoming fatigued from excessive hours of overtime. OCMIs should consider all relevant information described in 20.C in establishing required manning levels. While there may be no definitive, scientific basis for a maximum workhour limit for vessel crewmembers, the OCMI has the discretion to impose manning levels based on a specified reasonable workhour limit taking into account fatigue and other human factors.

A twelve hour work day, applied in a manner similar to the above workhour limit for tankers, is considered a reasonable workhour limit for other classes of vessels. It is recommended that the OCMI consider this workhour limit in establishing manning levels for non-tankers, adjusting for vessel specific factors that might either alleviate or exacerbate fatigue. Likewise, the OCMI may appropriately consider working conditions and workhour limits established through a collective bargaining agreement in arriving at a final manning determination. (See chapter 24 of this volume for additional discussion regarding working conditions.)

3. Enforcement.

Coast Guard boarding officers/marine inspectors, during boarding or inspection activity on board a vessel shall:

a. Ensure that they make general inquiries concerning the working conditions on board the vessel.

b. Make a specific effort on tankers to ascertain whether the vessel's crew is complying with the work hour provisions of 46 U.S.C. 8104(n) and rest requirements of STCW as found in 46 CFR 10.51111. A review of vessel work logs, maintenance records, and crew interviews should be conducted at each vessel inspection and reinspection to validate adequacy of the manning level to maintain the vessel in safe operating condition.


Marine Safety Manual III Chapter 22

C. Mates.

A number of statutory provisions in Title 46, U.S. Code dictate the minimum number of licensed mates required for a vessel. The statutes predominately specify manning level based upon watchkeeping requirements. In establishing the minimum number of mates required for safe operation, the Officer in Charge, Marine Inspection (OCMI) should consider a vessel's total operational requirements, such as cargo handling, emergency evolutions, and preventive maintenance in addition to mandated levels of manning. The sample manning scales in chapters 21 and 26 have been prepared following this philosophy.

1. Minimum Number Of Mates.

46 U.S.C. 8301 requires a minimum number of mates based on vessel tonnage, length of voyage, and in some cases upon vessel type. These mate manning levels are not discretionary. An OCMI may not authorize fewer mates than provided within this statutory section.

2. Master, Mate, Or Engineer License Requirement.

46 U.S.C. 8304 requires persons serving as master, mate, or engineer on any vessel operating on the high seas (e.g., operating beyond the boundary line) of 200 gross tons or over to hold a license appropriate for the route and tonnage of the vessel.

3. Working Conditions And Watch Requirements.

46 U.S.C. 8104 has a number of subsections concerning working conditions and watch requirements that may result in a higher number of mates being assigned than might otherwise be required by 46 U.S.C. 8301.

a. Section 8104(a) requires a minimum rest period for the officer in charge of the navigation watch upon a vessel's departure from port or immediately after the vessel departs. A sufficient number of mates must be assigned to ensure all in-port duties may be accomplished safely and a rested crew is available for departure. 46 CFR 15.11 also provides rest hour provisions for vessels operating beyond the boundary line.


46 CFR 15.710  Working hours.

    In addition to prescribing watch requirements, 46 U.S.C. 8104 sets limitations on the working hours of licensed individuals and crew members, prescribes certain rest periods, and prohibits unnecessary work on Sundays and certain holidays when the vessel is in a safe harbor. It is the responsibility of the master or person in charge to ensure that these limitations are met. However, under 46 U.S.C. 8104(f), the master or other licensed individual can require any part of the crew to work when, in his or her judgment, they are needed for:
    (a) Maneuvering, shifting berth, mooring, unmooring;
    (b) Performing work necessary for the safety of the vessel, or the vessel's passengers, crew, or cargo;
    (c) Saving of life on board another vessel in jeopardy; or,
    (d) Performing fire, lifeboat, or other drills in port or at sea.

46 USC 8104. - Watches

(a)  An owner, charterer, managing operator, master, individual in charge, or other person having authority may permit an officer to take charge of the deck watch on a vessel when leaving or immediately after leaving port only if the officer has been off duty for at least 6 hours within the 12 hours immediately before the time of leaving.

(d) On a merchant vessel of more than 100 gross tons as measured under section 14502 of this title, or an alternate tonnage measured under section 14302 of this title as prescribed by the Secretary under section 14104 of this title (except a vessel only operating on rivers, harbors, lakes (except the Great Lakes), bays, sounds, bayous, and canals, a fishing, fish tender, or whaling vessel, a fish processing vessel of not more than 5,000 gross tons as measured under section 14502 of this title, or an alternate tonnage measured under section 14302 of this title as prescribed by the Secretary under section 14104 of this title, yacht, or vessel engaged in salvage operations), the licensed individuals, sailors, coal passers, firemen, oilers, and water tenders shall be divided, when at sea, into at least 3 watches, and shall be kept on duty successively to perform ordinary work incident to the operation and management of the vessel. The requirement of this subsection applies to radio officers only when at least 3 radio officers are employed. A licensed individual or seaman in the deck or engine department may not be required to work more than 8 hours in one day.

(e) On a vessel designated by subsection (d) of this section
a seaman may not be -
(A) engaged to work alternately in the deck and engine departments; or
               (B) required to work in the engine department if engaged for deck department duty or required to work in the deck department if engaged for engine department duty;

(2) a seaman may not be required to do unnecessary work on Sundays, New Year's Day, July 4th, Labor Day, Thanksgiving Day, or Christmas Day, when the vessel is in a safe harbor, but this clause does not prevent dispatch of a vessel on a voyage; and

(3) when the vessel is in a safe harbor, 8 hours (including anchor watch) is a day's work.

(f) Subsections (d) and (e) of this section do not limit the authority of the master or other officer or the obedience of the seamen when, in the judgment of the master or other officer, any part of the crew is needed for -

(1) maneuvering, shifting the berth of, mooring, or unmooring, the vessel;

(2) performing work necessary for the safety of the vessel, or the vessel's passengers, crew, or cargo;

(3) saving life on board another vessel in jeopardy; or

(4) performing fire, lifeboat, or other drills in port or at sea.