The mathematical error in Nigeria’s sea area claim

By Navy Capt. Sunday Daniel Atakpa

The reference to Nigeria’s jurisdictional sea area has always been on the basis of a 420 nm coastline and 200 nm Exclusive Economic Zone (EEZ) limit.  A total sea area of 840,000 sq nm is generated using a Length x Breadth formula meant for establishing the Area of a regular solid rectangular body – a case of a correct mathematical formula wrongly applied. This is because while the application of the formula used may hold sway for any rectangular body, it cannot be true for an irregular and ambulatory body such as Nigeria’s indented coastline. This error, which may amount to claiming more or less space than Nigeria’s entitled sea area, has been spread through lectures, presentations and discussions from as far back as cognitive Service memory can recall.

According to sources, Nigeria’s coastline stretches 420 nm along its concavities. To apply the straightforward regular solid body formula to establish the sea area claim would mean stretching Nigeria’s indented coastline to achieve a straight line. Although 420 nm is an absolute number, it would nonetheless be longer than Nigeria’s eastern and western coastal boundaries when laid out as a straight line. The implication of this is that Nigeria’s maritime East and West limits would stretch into Cameroon and Republic of Benin’s maritime territories respectively. It is also possible that it may stretch beyond Republic of Benin’s comparatively smaller coastline of 65 nm depending on the eastern limit used. Furthermore, such a straight line would have its tangent at the outermost edge of the Niger Delta fan – actually, from the low water line determined as the Lowest Astronomical Tide (LAT) in accordance with Article 5 of the 1982 United Nations Convention on the Law of the Sea (UNCLOS). The breadth of the 200 nm EEZ limit would thus be determined from this tangent (outermost edge) seaward. Another implication of this is that all the indented sea area from the tangent (outermost edge) landward, left and right of it, would be unaccounted for.

The afore stated criteria may present a seemingly logical argument that the maritime space, after all, is an approximated space. This perhaps must have accounted for the use of ‘about’ in the establishment of the sea area by its proponents based on the wrong formula use. However, from a mathematical and scientific standpoint, an approximation made on the basis of a wrong formula principle is illogical and wrong. This is because mathematical approximations, wherever and whenever applied, are to be made on correctly applied formulae. Hence, the formula must first be correct and applicable to the problem before the approximation can hold. Therefore, the use of ‘about’ in the Nigerian sea space claim would have been appropriate if used to account for the errors inherent in the tortuous scoping of the coastal concavities. Not on wrong formula as has been the practice over the years. To do otherwise would be to beg the question and portray whosoever is asserting as mathematically inept before any discerning audience.

To establish a credible sea area for Nigeria, the correct mathematical operation must be applied. For such an irregular and ambulatory coastline, the sea area has to be derived through a complex string of differential calculus which will accurately account for the coastal concavities and produce a credible sea area that can stand the test of mathematical accuracy. There can be no shortcut to it. The starting point would be to re-evaluate the 420 nm coastline claim in the light of the boundary delimitations effectuated with Cameroon in the Bakassi area, if it has impacted the coastline in any way.

The need to have an accurate sea area claim could not have come at a better time than now for 2 reasons. Firstly, Nigeria recently submitted its information on the limits of the continental shelf beyond 200 nm to the Commission on the Limits of the Continental Shelf (CLCS) in line with the provision of Article 76 of UNCLOS. The intent is to claim more sea space up to a maximum of 350 nm limit from the coastline. For Nigeria to be able to establish how much sea space it would have gained on the basis of CLCS recommendations, she must have an accurate extant sea area data on which to benchmark the gain.

Secondly, the International Tribunal on the Law of the Sea (ITLOS) in its 2012 operative judgement in the Bangladesh/Myanmar case, proved that concavities play critical role in the determination of national sea space. While Myanmar advocated the use of equidistance line over a coastline whose concavities were ignored, Bangladesh advanced its argument for the use of angular bisector line which accurately accounted for the peculiar concavities of the Bay of Bengal.  ITLOS applied both criteria. However, the outcome was a sea claim largely in favour of Bangladesh having due regard to the Bay of Bengal concavities.

In order to properly account for every mile of Nigeria’s maritime space, it is important that Nigeria’s coastline should be accurately determined and the sea space correctly established through the appropriate calculus.  This is the only means by which the skewed sea area claim currently bandied would be corrected.


Atakpa is the Chief Instructor, Joint Warfare Division, Depratment of Joint Studies, Armed Forces Command and Staff College, Jaji. 

Copyright 2017 Ships & Ports Ltd. Permission to use quotations from this article is granted subject to appropriate credit given to as the source.