5 The compatibility of the crossing rule and the narrow channel rule reduces the role of prediction in determining the applicable rules:
An often ignored objective of the COLREGS is to eliminate guess-work by coordinating the actions of vessels that encounter one another. Through interpretation, it is possible to conciliate between the crossing rule and the narrow channel rule, so as to minimize the risk of collision without having to dis-apply either one of them. It also lessens the role that prediction of intentions or navigation plays in determining the applicable rules in equivocal crossing encounters in or near narrow channels. Marsden and Gault cites a number of cases,(1) Cited cases in Marsden and Gault: The Leverington (1886) 11 P.D. 117; The Ashton [1905] P. 21; the State of Himachal Pradesh [1985] 2 Lloyd’s Rep. 573, affirmed [1987] 2 Lloyd’s Rep. 97, CA.decided before The Alexandra I, which have recognized the possibility for both the narrow channel rule and the crossing rule to be simultaneously applicable,(2) Andrew Tettenborn, John Kimbell, Marsden and Gault on Collisions at Sea, 15th edition, para 7-243, 7-244.although they note that one of the two rules may still be dis-applied.(3) Cited case in Marsden and Gault: The Jaroslaw Dabrowski [1952] 2 Lloyd’s Rep. 20.The hypothesis which this chapter explores is that the duties imposed by each of the narrow channel and the crossing rule are not inconsistent and, in some cases, are exactly the same. In most crossing situations involving narrow channels, the duties of the non-crossing vessel will quite often remain unaffected, regardless of whether or not the crossing rule applies (infra, 5.1 & 5.2). This is the case because in the majority of cases, the crossing vessel will also be the give-way vessel. The non-crossing vessel as the stand-on vessel will thus be required only to keep the course and speed that allows her to keep-to-starboard. As for the crossing vessel, complying with the crossing rule will often result in compliance with the narrow channel rule as well, since the duties under the two sets of rules are consistent with one another (infra, 5.3).