Rule 18: not a simple “pecking order”

by Jim Austin

    Recurring criticisms concerning the ColRegs most often relate to their arcane language, cross-referencing superimposed on convoluted sequencing (“notwithstanding a, b, c, etc.”) and ill-defined definition of terms: “close quarters,” “coming up with,” “narrow channel,” “safe speed” and the mother of all obfuscations, “not to impede.” While true that the variables of speed, approach aspect and vessel maneuverability blur precise boundaries, one might question the possibility of tightening up some parameters and uncluttering the verbiage. This effort will look a little more deeply into ColReg Rule 18, since, with one exception, that and Inland are nearly identical.

    One of the arguably more deceptive ColRegs is Rule 18, “Responsibilities Between Vessels.” Those studying for a Coast Guard license exam dutifully memorize the sequence from “Not Under Command” to “Seaplane/WIG.” Hidden within that “pecking order,” things are less orderly than they presume to be and their clarity is less than unrestricted.

    The rule opens with: “Except where Rules 9, 10 and 13 otherwise require…” so right out of the gate, a vessel has lost its presumptive clout in the hierarchy when any of those situations pertain; example, a vessel not under command (NUC) coming up astern of a sail vessel is not “stand-on” (although courtesy, if not prudence, would impel the sail skipper to recognize the other’s plight).
    Having passed the first hurdle, the sequence listed in virtually every text is as follows:

(a) not under command (NUC)
(b) restricted in ability to maneuver (RAM)
(c) vessel constrained by draft (ColRegs only)
(d) fishing
(e) sailing vessel
(f) power-driven vessel (including WIG operating on surface)
(g) seaplane (including WIG taking off/airborne/landing)

    In a very general sense, that is the way it is — sort of. Digging deeper, however, reveals booby traps. It has to be emphasized that the U.S. Coast Guard manual on the Rules (COMDTINST M 16672.2D) does not list “constrained by draft” in the sequence, but rather in a later subparagraph. Nevertheless, elsewhere they are most often listed as above.
    Easily overlooked and bearing repetition is that preamble to the text of the rule — that if they are operating in three specific situations: (a) a narrow channel (Rule 9), (b) a traffic separation scheme (Rule 10) or (c) overtaking (Rule 13) — the priority sequence of Rule 18 doesn’t apply.
    Despite the responsibility hierarchy implied by the lettered sequence of vessel status — fishing above sail (d before e), sail above power (e before f), etc. — that does not hold for NUC and RAM (a is NOT to be considered to be above b); they are in a co-responsible (if you will) status. This has confounded exam-takers for years and despite pleas to clarify, the Rules of the Road Committee of NAVSAC some years ago refused, voting down a motion to request the IMO “to look at Rule 18 and consider the confusion that it causes.” Apparently, the belief was that if there was any conflict, application of Rule 2 would solve it.

    Rule 18 (a) states that sail (e) and power-driven vessels (f) “shall keep out of the way of” the vessels outranking them in the pecking order. Not quite the same with fishing. The terminology of 18 (c) subtly shifts to “a vessel engaged in fishing when underway shall, so far as possible, keep out of the way of a vessel not under command or restricted in ability to maneuver.” While it’s true that a fishing vessel in the midst of certain evolutions puts a severe limit on her ability “to keep out of the way of,” the same might reasonably be said of a NUC or RAM vessel whose maneuvering ability is impaired by definition. Nevertheless, and for uncertain reason, the shade of difference in the terminology gives attorneys wiggle room in the courtroom.

    “Constrained by draft” doesn’t appear in the ColRegs pecking order directly (as noted above) but more as an afterthought in paragraph (d) (i) and (ii) of Rule 18, specifying that any vessel other than NUC and RAM shall “avoid impeding” such vessel (“impeding” not defined). The critical point being that constrained by draft, in and of itself, does not confer “stand-on” status despite the definition of such vessel in Rule 3 (h) as being “severely restricted in her ability to deviate from the course she is following.”

    Thus, the hampered vessel, approached broad on the starboard bow by another below NUC and RAM in the above order must, if a risk of collision exists and despite being “impeded,” is now within the clutches of Rule 8 (f) (iii), requiring her to maneuver as required for a give-way vessel (being crossed in this example). That same rule does reassert the rogue vessel’s obligation not to “impede” and further, to anticipate the hampered vessel’s escape maneuver so as not to take a conflicting one 8 (f) (ii).
    More often than not, a case being tried under admiralty jurisdiction is argued by teams of attorneys supremely versed in maritime law before qualified judges. In addition, if in a British court, the bench may enlist the assistance of nautical assessors, most often Trinity House Elder Brethren. Their deliberations frequently contest over days and weeks not necessarily whether the watch officer complied with the rule, but which rule applied and what does the rule really mean (example: “coming up with” in an overtaking situation.)

    Meanwhile, on the bridge, the often-fatigued OOD/OOW may have had minutes to collect information, assimilate it while trying to block out all the other distractions in order to concentrate on the approaching threat. If it takes a court weeks or more to figure it out, is it reasonable to expect the IMO (in the case of the ColRegs) to put it in English — or the language of choice — with fewer “notwithstandings” or “if the case admits” or vague terminology such as “not to impede?”



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?
By Professional Mariner Staff