MarIus

5.2 Crossings or equivocal crossings in narrow channels:

In narrow channels, the most common scenario where two vessels may appear to be on a crossing course is when they meet near a bend. At that point, it is rather difficult for vessels to tell whether it is an actual crossing (Fig. 4.1.), where one vessel (Vessel B) does not intend on rounding the bend, or simply an equivocal crossing caused by the channel’s curvature, but which will resolve with a port-to-port passing, thanks to the keep-to-starboard requirement (Fig. 4.2.).

Interestingly, the risk of collision is much higher when the vessel that has the other on her starboard side (Vessel B) intends on crossing the narrow channel from one side to the other (Fig. 4.1.). If the putative stand-on vessel (Vessel A) under the crossing rule decides to go outside the boundaries of the narrow channel, it usually causes no hindrance to the other vessel (Fig. 4.3.). The crossing rule would apply only in the scenario where vessel A alters to port with the intention of crossing mid-channel to the other side (Fig. 4.3-bis), in which case vessel A would be the give-way vessel under the crossing rule.

Similarly, when a vessel crosses a narrow channel outside of the situation involving a natural curving narrow channel, the crossing vessel will in most cases be the give-way vessel under the crossing rule (Fig. 5.1. and 5.2.). Only in a case where the crossing vessel is crossing from the same side as the vessel following the course of the narrow channel (Fig. 5.3.), will the give-way vessel not be the crossing vessel.

As we can see, and with the exception of the encounter in Fig. 5.3., where two vessels appear to be on a crossing course, regardless of whether one or both vessels intend on actually crossing or not, the crossing vessel happens in most cases to be the give-way vessel. For the non-crossing channel vessel, application of the crossing rule has little effects on her duties once again, similarly to the different scenarios at the entrance of narrow channels. As the stand-on vessel, the duty will simply be to maintain the course and speed necessary to keep-to-starboard of the narrow channel. It is mostly the duty of the potentially crossing vessels, which may change depending on whether or not the crossing rule applies. However, even in a case where the crossing rule applies, it can be argued that the duties imposed on the give-way vessel by the crossing rule are capable of producing the best results when applied concurrently with the narrow channel rule.