The International Navigating Limits (INL), formerly Institute Warranty Limits (IWL), were revised and renamed by the Institute of Chartered Underwriters in London, United Kingdom, in 2000 and became effective in November 2003.

The term IWL is still found in charter parties and related documents and should be updated to refer to INL because there are significant changes in some areas.

To “breach” INL is to navigate into or through one of the either seasonal or permanently “excluded areas” without advising the hull insurance underwriters and without paying the additional insurance premia which will void the vessel’s hull insurance cover.

Areas permanently excluded include Polar Regions, North and South, typically above latitude 50˚ or 52˚. Also permanently excluded are St. Lawrence Seaway and Great Lakes, Aleutian and Queen Charlotte Islands, and the Bering Sea with conditions.

The seasonally excluded areas, typically the Northwest coast of North America (Alaska), Northwestern Russia, the Baltic, and the Northeast coast of North America (Gulf of Saint Lawrence and St. Lawrence River) cannot be navigated during the winter season under summer hull insurance conditions. The one and only reason is the ice. Ice is known to be extremely hazardous to ships, and too many ships are not fitted for navigation in ice and even if they are, the risk of damage is high. To navigate in such areas, the shipowners have to contact their hull underwriters to get permission to enter such an area or, as it is often expressed, they breach the INL. This is short for International Navigating Limits, the set of clauses that regulates where the ship may trade under English Hull Conditions (Institute of Chartered Underwriters).

Note however: all shipowners are not insured according to English Hull Conditions and the trading warranties may differ depending on the conditions of cover. Thus it is proper to check the trading warranties agreed upon, especially since charterparties very often refer to the INL, which may not be the conditions as the owner’s hull insurance policy.


Unless and to the extent otherwise agreed by the Underwriters in accordance with Clause 3 below, the vessel shall not enter, navigate or remain in the areas specified below at any time or, where applicable, between the dates specified below

(both days inclusive):

Area 1 - Arctic

  • North of 70⁰N
  • Barents Sea except for calls at Kola Bay, Murmansk or any port or place in Norway, provided that the vessel does not enter, navigate or remain north of 72⁰30’ N or east of 35⁰ E

Area 2 – Northern Seas

  • White Sea;
  • Chukchi Sea.

Area 3 - Baltic

  • Gulf of Bothnia north of a line between Umea (63⁰ 50’ N ) and Vasa (63⁰ 06’ N ) between 10th December and 25th May.
  • Where the vessel is equal to or less than 90,000 DWT, Gulf of Finland east of 28⁰ 45’ E between 15th December and 15th May.
  • Vessels greater than 90,000 DWT may not enter, navigate or remain in the Gulf of Finland east of 28⁰ 45’ E at any time.
  • Gulf of Bothnia, Gulf of Finland and adjacent waters north of 59⁰ 24’ N between 8th January and 5th May, except for calls at Stockholm, Tallinn or Helsinki.
  • Gulf of Riga and adjacent waters east of 22⁰ E and south of 59⁰ N between 28th December and 5th May.

Area 4 - Greenland territorial waters.

Area 5 – North America (east)

  • North of 52⁰ 10’ N and between 50⁰ W and 100⁰ W
  • Gulf of St. Lawrence, St. Lawrence River and its tributaries (east of Les Escoumins), Strait of Belle Isle (west of Belle Isle), Cabot Strait (west of a line between Cape Ray and Cape North) and Strait of Canso (north of the Canso Causeway), between 21st December and 30th April.
  • St. Lawrence River and its tributaries (west of Les Escoumins) between 1st December and 30th April.
  • St. Lawrence Seaway.
  • Great Lakes.

Area 6 – North America (west)

  • North of 54⁰ 30’ N and between 100⁰ W and 170⁰ W
  • Any port or place in the Queen Charlotte Islands or the Aleutian Islands.

Area 7 – Southern Ocean South of 50⁰S.

except within the triangular area formed by rhumb lines drawn between the following points

  • 50⁰ S; 50⁰ W
  • 57⁰ S; 67⁰ 30’ W
  • 50⁰ S; 160⁰ W

Area 8 – Kerguelen/Crozet Territorial waters of Kerguelen Islands and Crozet Islands.

Area 9 – East Asia

  • Sea of Okhotsk north of 55⁰ N. and east of 140⁰ E between 1st November and 1st June.
  • Sea of Okhotsk north of 53⁰ N. and west of 140⁰ E between 1st November and 1st June.
  • East Asian waters north of 46⁰N. and west of the Kurile Islands and west of the Kamchatka Peninsula between 1st December and 1st May.

Area 10 – Bering Sea Bering Sea except on through voyages and provided that

  • the vessel does not enter, navigate or remain north of 54⁰ 30’ N; and
  • the vessel enters and exits west of Buldir Island or through the Amchitka, Amukta or Unimak Passes; and
  • the vessel is equipped and properly fitted with two independent marine radar sets, a global positioning system receiver (or Loran-C radio positioning receiver), a radio transceiver and GMDSS, a weather facsimile recorder (or alternative equipment for the receipt of weather and routeing information) and a gyrocompass, in each case to be fully operational and manned by qualified personnel; and
  • the vessel is in possession of appropriate navigational charts corrected up to date, sailing directions and pilot books.


In the event the vessel is in breach of Clause 1 above, the Underwriters shall not be liable for any loss, damage, liability or expense arising out of or resulting from an accident or occurrence during the period of breach, unless notice is given to the

Underwriters immediately after receipt of advices of such breach and any amended terms of cover and any additional premium required by them are agreed.


The vessel may breach Clause 1 above and Clause 2 shall not apply, provided always that the Underwriters’ prior permission shall have been obtained and any amended terms of cover and any additional premium required by the Underwriters are agreed.

The International Navigating Limits in Maritime Optima:

Text from Gard and Andrew Liu & Co Ltd

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