Danger lurks to starboard II

Tight crossing/overtaking
    Lest the reader think that a text on the Navigation Rules has to be humorless, consider a quote from Farwell’s Rules of the Nautical Road (U.S. Naval Institute) concerning the crossing aspect: “When we consider the apprehensive state of mind that so often dominates the bridge watch standers on vessels in these cases, particularly on the stand-on vessel, we are almost inclined to believe that the crossing situation should be outlawed.”

    The angst alluded to in Farwell often concentrates in two narrow zones — where crossing borders head-on (Rules 15/14) and overtaking (Rules 15/13). Although danger exists to both port and starboard, it’s the latter that merits special attention. This article concerns overtaking under the ColRegs (excluding narrow channels). Those and Inland are for another time.

    Rule 13 (Overtaking) can reasonably be condensed to:
(a) If you’re overtaking, you’re give-way.
(b) You’re overtaking if you are “coming up with” and can see a stern light but not masthead(s) or sides (or their daytime equivalent of 22.5º degrees abaft the beam).
(c) If you’re not sure if you’re overtaking — the rules say you are.
(d) A bearing shift as you overtake doesn’t change things; you’re still give-way until past and clear; if it started as white and now is green … see red.

    A look at the crossing boundary to starboard is appropriate because, as noted in the last Rules of the Road newsletter, that’s where special danger lurks — that of conflicting maneuvers resulting from situational ambiguity. The situation of vessels meeting slightly to starboard of each other in the murky boundary between head-on and crossing was covered last time. This one will look farther aft, to the vessel approaching at or close to 22.5º abaft the beam, the vessel that may see white and then perhaps a questionable green flicker off her port bow. The watch officer approaching must decide whether it’s give-way (overtaking) or stand-on (crossing) while up ahead, that bridge watch has to assume how the other is interpreting the situation.

    Why the attention to own vessel’s starboard sidelight sector edge as opposed to port? If a vessel is overtaking to port, she’s give-way befitting that aspect. Drawing foreword, she enters the sector that — if it were a crossing situation at the outset — would still make her the give-way vessel as she would be to port (and as a further requirement of the Rule, she maintains her give-way status until finally past and clear — or as Sweeny and Healy, in their The Law of Marine Collision, quote Marsden’s Collisions at Sea: “Once an overtaking ship, always an overtaking ship.” So, either way, she maintains give-way status when overtaking to port. Another way to think of it: she’d be seeing white and then red all the way until past and clear.

    Now consider a vessel overtaking to starboard at or near the cutoff sector of the green sidelight of the vessel being overtaken — a situation ripe for confusion. Yaw in a seaway, variability on the sidelight’s visible arc and range, etc., may entice the OOD/OOW of the approaching vessel, uncertain as to what is seen, to assume the privilege of a stand-on vessel to starboard in a crossing situation — and to act accordingly. However, the overtaken vessel may see it as overtaking and maintains course and speed — thus both steam into the trap of situational ambiguity and the clutches of extremis at best, collision at worst — ambiguity begetting conflicting maneuvers. A variation on that theme is the vessel that accepts the burden of give-way while overtaking (to starboard) but once she has overhauled into the overtaken vessel’s green sector, assumes she is now stand-on in a crossing situation. Anticipating that, paragraph (d) of Rule 13 prohibits such an assumption.

    Vessel A was steaming on course 341º T/12 knots. The lookout sighted vessel B about 30º abaft the starboard beam, estimated at three miles; about 15 minutes later (one hour before collision) he noted red coming into view. Vessel B at the time was said to have been on 331º/14.5 knots but this was later questioned at trial. A considered herself as being overtaken, thus the stand-on vessel; while B saw it otherwise, with A as give-way in a crossing situation.

    Approximately 30 minutes before collision, B was reported abeam at about one mile, and 15 minutes later was about 30º forward of the beam. At that point, A’s watch officer ordered hand steering and attempted contact with B by blinker (no response); shortly later he slowed and stopped engines. Hearing one short blast from B, he put A’s engines full astern. Collision occurred some 73 minutes after first sighting with A’s bow striking B’s port quarter; damage, of course, but fortunately no casualties. The case went before an English court sitting in admiralty.

    Relying on the precedent set by a century-old case, the judge decided that since at the time of first sighting and despite being on an overtaking course, B had not “come up with” A, and since there was no risk of collision, “overtaking” wasn’t in effect. Upon the advice of Trinity House Elder Brethren in their role as nautical assessors, he concluded that such risk hadn’t developed until B was abeam at a mile; at that point the aspect was crossing and now ensnared by the rules, A was give-way as the vessel to port. In agreeing that B might have taken avoiding action sooner, the percent damage was allocated A: 75, B: 25. Appeal followed.

    It would seem that overtaking would be the safest approach since its typically lower closing speed provides longer time for judgment, decision and maneuver, but several things belie that assumption. To start with, the vessel that is overtaking (thus give-way) is, at least initially, calling the shots: which side, at what distance, at what speed, etc. Meanwhile, if being overtaken to starboard, the stand-on vessel is burdened with at least two assumptions to consider: (a) that the approaching vessel sees herself as overtaking (and not crossing, which would shift responsibility) and (b) that if the oncoming vessel is uncertain as to which, she’ll assume overtaking as mandated by Rule 13(c).

    To start with, Rule 13 isn’t as helpful as it might be, witness the fact that much courtroom debate has concerned itself as to when the rule starts to apply. As pointed out in Farwell: “(n)either the text of the rules nor decisions of the courts have provided a definitive answer to the question of whether risk of collision is an implied prerequisite to application of the overtaking rule.” The other approach aspects (meeting and crossing) employ the trigger phrase “so as to involve the risk of collision” but that’s absent in ColReg/Inland Rule 13, replaced by the arguably less illuminating “coming up with.”

    Predictably, the meaning of that phrase has been the subject of much legal distress. Capt. Richard Cahill in his Collisions and Their Causes (The Nautical Institute) suggests that “from a practical standpoint it would seem that an overtaking ship has ‘come up’ with the vessel she is overtaking once she has reached a position where she is committed to passing on a particular side.” While not defined as such within the rules, it’s an attempt to give substance to otherwise vague terminology.

    But back to the courtroom. The appeal involved much discussion about lateral distances, converging courses, current/wind effect on heading versus course, etc., but in the end seemed to throttle down to the question as to whether the overtaking rule applies before the risk of collision exists and that’s where “coming up with” comes up. Where/when does that commence and if that’s the trigger for the rule, does it trap both vessels simultaneously? The court held that, in fact, B was coming up with A, putting the former in the role of overtaking and give-way. The trial court’s allocation of damages was reversed.

    The logic used by the appeals court seemed to be that although the point at which the risk of collision arises is, in effect, a boundary (for want of a better word) within which the Rules governing meeting (14) and crossing (15) apply, the boundary at which Rule 13 (overtaking) is not defined by “the risk of collision” but rather by “coming up with.” Consequently, it may take effect earlier in the approach, but that begs the question: When is that and does it ensnare both vessels simultaneously?

    If the reader anticipated enlightenment, it’s not to come. The court opined that when exactly “coming up with” takes effect “may not always be easy to determine but we see no reason to suppose that it will be any more difficult than the decision as to when the situation involves the risk of collision” — a glossy way of saying “you’re on your own.”

    Having cast light on the meaning of “coming up with,” Capt. Cahill, quoting the Appeals Judge Sir David Cairns, helps further by suggesting just when it takes effect. A vessel shall be considered as overtaking within the meaning of the Rules, he writes, when “coming up with another vessel from such a position that her stern light is in view on first sighting and though while risk of collision may not exist at the time, it might develop if both vessels hold their courses and speeds.”

    In summary, a vessel approaching just aft of the starboard beam should arouse a healthy anticipation of potential trouble. One sees it as overtaking and the other as crossing with assumption meeting confusion at the collision bulkhead and no one wins. So — keep a weather eye on that vessel overtaking, especially if on the starboard quarter.

About the Author 
Following graduation from the U.S. Naval Academy, Jim Austin served aboard both a destroyer and cruiser with duties that included navigator, assistant CIC (combat information center) officer and air intercept controller. He subsequently worked on the submarine launched ballistic missile program for General Electric Co.’s Ordnance Division. He holds a U.S. Coast Guard master’s license and writes frequently on ship collisions as seen through the twin lenses of the navigation rules and maritime law. He’s a retired physician living in Burlington, Vt.
Questions for Jim Austin?  editors@professionalmariner.com

By Professional Mariner Staff