46 CFR § 35.05-15 - Tank vessel security—TB/ALL.
(a) Manned tank vessel. At least one member of the crew of a manned tank vessel shall be on board at all times except when the vessel is gas free or is moored at a dock or terminal at which watchman service is provided.
(b) Unmanned barge.
(1) The owner, managing operator, master, and person in charge of a vessel towing a tank barge that need not be manned, and each of them, shall be responsible for monitoring the security and integrity of the tank barge and for ensuring adherence to proper safety precautions. These responsibilities include, but are not limited to—
(i) Ensuring that any tank barge added to the tow has all tank openings properly secured; has its freeing-ports and scuppers, if any, unobstructed; meets any loadline or freeboard requirements; and neither leaks cargo into the water, voids, or cofferdams nor leaks water into the tanks, voids, or cofferdams;
(ii) Ensuring that every tank barge in the tow is properly secured within the tow;
(iii) Ensuring that periodic checks are made of every tank barge in the tow for leakage of cargo into the water, voids, or cofferdams and for leakage of water into the tanks, voids, or cofferdams;
(iv) Knowing the cargo of every tank barge in the tow, any hazards associated with the cargo, and what to do on discovery of a leak;
(v) Ensuring that the crew of the vessel know the cargo of every tank barge in the tow, any hazards associated with the cargo, and what to do on discovery of a leak;
(vi) Reporting to the Coast Guard any leaks from a tank barge in the tow into the water, as required by 33 CFR 151.15; and
(vii) Ensuring that the crew of the vessel and other personnel in the vicinity of the tank barges in the tow follow the proper safety precautions for tank vessels, and that no activity takes place in the vicinity of the barges that could create a hazard.
(2) When a barge is moored and contains more oil than the normal clingage and unpumpable bilge or sump residues, the barge must be kept under surveillance by a person responsible for the security of the barge and for keeping unauthorized persons off the barge.
(3) When a barge is moored and contains no oil but is not gas free:
(i) It must be maintained under surveillance as required in paragraph (b)(2) of this section; or
(ii) All cargo tank hatches must be clearly marked in not less than three inch lettering “Danger—Keep Out,” and all hatch covers must be closed and dogged down in such a way that the hatch cannot be opened by the use of bare hands alone.