Safety update

December 2010 Fishing vessels drifting at night

This safety update is issued to highlight the legal requirements for fishing vessels, and any other ship, if they apply the practice of drifting at night.

Key issues

It has been noted that elements of the fishing industry, such as long-liners fishing for tuna, regularly adopt the working practice of drifting for periods of the night.

A recent accident where a ship ended up stranded on a beach, and previous vessel collisions, has once again highlighted the risks associated with this practice.

Drifting without setting a watch-keeper is a practice frequently being adopted by two person-crews to permit both persons to sleep between fishing operations. During this practice the wheelhouse is often left unattended and some vessels are using the navigational lights which communicate that the vessel is “not under command” (NUC).

There are a number of hazards associated with this practice and a number of elements that do not comply with maritime rules and the collision prevention regulations.

Watch keeping and lookout

Keeping an efficient lookout is an important legal requirement in rule Part 22 – Collision Prevention:

22.5 Look-out

Every vessel must at all times maintain a proper look-out by sight and hearing as well as by all available means appropriate in the prevailing circumstances and conditions, so as to make a full appraisal of the situation and the risk of collision.

All commercial vessels, whether they are drifting or not, need to keep an effective look-out.

Navigation lights

A ship which intentionally stops its main propulsion engine and drifts has not broken down, it has not been exposed to “exceptional circumstance” or been disabled. If there is no exceptional circumstance involved in the decision to drift, the skipper must appreciate that they are breaching maritime law if they indicate that the vessel is ‘not under command’ through the use of two vertical round red lights.

The correct lights for a drifting vessel, which has not been exposed to exceptional circumstance, are the normal masthead, side and stern lights. The anchor light must not be shown for this circumstance. Deck lights may be switched on and can also be effective at increasing the range at which the vessel may be detected.


A drifting vessel must keep out the way of an approaching vessel when required to do so by the international collision regulations and NZ maritime rule 22.8. An approaching ship may not realise the vessel is drifting. For this reason, engines must be ready for immediate operation.

Fatigue management plans and sufficient manpower

The issue of fatigue management has been well communicated in NZ over the last few years. Supportive material is available on the MNZ website and includes the following material on “Understanding Fatigue” and “The Guide to Fatigue Management for Fishing Boats”:

Understanding Fatigue[PDF: 84Kb, 2 pages]

The Guide to Fatigue Management for Fishing Boats[PDF: 380Kb, 28 pages]

Any ship exposed to the hazards of fatigue, through its chosen operation and crew numbers, are required to identify the hazard, document it in the ships safety management system (or manual) and apply adequate measures to mitigate the risks from fatigue. This is both a maritime rule requirement and a Health and Safety in Employment Act requirement.

Your SSM company can advise on how to apply fatigue management principles to your operations and how to document your working procedures onboard.

The number of crew onboard naturally assists in permitting rotational periods of work and rest. This is a problematic issue for smaller vessels which prefer to keep crew numbers as low as possible. The owner or operator must ensure that sufficient persons are onboard to adequately mitigate the safety risks from fatigue.

Location and forecasting

For obvious reasons any overnight drifting location must be carefully selected with full consideration to currents, tides, swell and wind forecasts. The distance to navigational hazards and main shipping routes should be carefully considered. A significant margin for error should always be applied to ensure that in the worst case scenario that all practical means has been taken to prevent an accident.

The vessel’s proximity to other ships should also be carefully assessed. Not all ships drift at the same rate and the practice of using of sea anchors or drogues may vary.

Key recommendations

  • The operational practice of drifting at sea is not recommended.
  • Always maintain 24 hour watch keeping while the ship is at sea and maintain a clear situation awareness at all times.
  • Always use the correct navigational lights at night and regularly check that they are working.
  • Have sufficient persons onboard to maintain watch-keeping duties and permit necessary sleeping periods.
  • Develop, implement and maintain a ‘fatigue management plan’ for your vessel and crew and explain how that plan will be applied onboard at the start of each trip.
  • If fatigue cannot be managed in a reasonable manner for the operations being undertaken, then additional numbers of crew are recommended to permit appropriate sleep periods.
  • Stay aware for the effects of fatigue and take appropriate action when it becomes a safety hazard.

Original source content - Safety Bulletin Issue 24, December 2010: Fishing vessels drifting at night.

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