I have to own up to a particular interest in Section III - Conduct of vessels in restricted visibility. It was the perception that few mariners understood the dictates of Rule 19 back in 1989 that set me off on the path of analysing people's response to the Rules in more detail. At that time, I conducted a survey similar in format to the scenarios presented here, purely on the understanding of Rule 19. Incredibly, the results of that survey have changed very little today, both show something approximating to an 80 per cent misunderstanding of the poor visibility rule. The distribution of answers, right or wrong, are almost identical.

Referring back to previous discussion on the understanding of Rule 8(f), it could be said perhaps, that there may be some excuse for the provisions of Rule 8(f) not impacting on mariners to any great extent, as it was a later 'add-on' in 1989. The same excuse cannot be made for the misconstruing of Rule 19: after all this has been the law since the 1972 Rules came into operation in 1976. How can we explain such a large proportion of mariners still ignorant of its provisions some 27 years later?

Dual action

When looking closely at the practical application of Rule 19, two issues stand out, the first of which is so fundamental it concerns the very concept on which Rule 19 is based: that of dual action. The fact is, a very high proportion of officers at sea remain blissfully unaware that, in any poor visibility situation, when ships are not in sight of one another, the rule requires both vessels to take action.

In the case of Scenario 3, approximately one third of the respondents expected the target to stand-on as per the clear visibility situation. Fewer than a quarter picked the correct action for both vessels to alter to starboard.

Incidentally, to date, whenever the subject of dual action has been mooted as a change in the basic philosophy for the Colregs, (The latest being David Thomas' The Fatal Flaw), it has inevitably aroused a storm of protest in defence of the Colregs as they stand. However it has been interesting to note, that these vociferous proponents of single action, ie, one vessel stand-on, also seem to be oblivious to the fact that the Rules already contain a dual action system sanctioned by Rule 19. If dual action is so wrong and so inimical to the conceptual basis of the Colregs, why have we seen fit to incorporate it in the 'not in sight' condition?

The beam problem

The second problem causing apparent difficulty is not so fundamental as the first but equally widespread it would seem. This concerns a vessel on the beam when interpreting the requirements of Rule 19(d). To quote the paragraph in full:

Invariably sub-clause 19(d)(ii) is erroneously taken to mean any vessel abeam or abaft the beam. The potential for confusion lies in the way the construction of the paragraph tends to obscure the fact that (ii) refers back to the initial part of the paragraph as of course does (i). It is likely that if these sub-clauses were reversed in order, similar confusion would arise with any vessel appearing forward of the beam.

The operative clause here is - shall determine if a close-quarters situation is developing and/or risk of collision exists, both the following sections d(i) and d(ii) are subordinate to it. If a close quarters or risk of collision exists forward of the beam then a port alteration is to be avoided. If a close quarters or risk of collision exists with a target abeam or abaft the beam then an alteration towards it should be avoided. If the latter situation presents no threat (as in the case of the starboard target in Scenario 3.) and provided it is safe and prudent to do so, an alteration towards is perfectly legitimate. Rule 19(d) simply does not apply to that vessel.

Scenario 3

With the above in mind, Scenario 3 was deliberately designed to test these errors and the results would appear to unequivocally support the hypothesis.

Both true and relative vector radar displays (Figure 1) provide sufficient information to ascertain the situation and take appropriate action. The vessel to port is on a steady bearing and the relative vector shows collision in approximately eight minutes from a position roughly half a point forward of the beam. This puts the requirement for action firmly within the provisions of Rule 19(d)(i). Both own vessel and the target have each other forward of the beam and both are required to avoid altering to port. This would suggest that if there is no other impediment, both vessels should alter to starboard. But is this possible for the own ship?

The target on the own ship starboard beam is four miles off and overtaking slowly on a parallel course, does this therefore constitute an impediment to a starboard alteration towards it? As explained above the answer is no. From the Rule's point of view, the vessel is not a collision or close quarters risk, therefore 19(d)(ii) does not apply. Nevertheless purely from a safe seamanship viewpoint, is it a safe action to take? Again there is no problem, the target is faster and therefore any alteration away from a parallel course with it can only serve to increase the size of the overtaking relative vector. The effect of any starboard alteration will also angle the subsequent target vector across the bow but it will still clear well ahead across the bow. (Figure 2 shows the effect of a clear alteration to starboard for own ship and the target).

Consequently the correct action for both vessels in this situation is to alter course to starboard. Slowing down or stopping are not illegal options but in this case are simply unnecessary manoeuvres.

Referring back to the answer code described in the August Colregs feature, the above equates to 2.2, 2.4, 2.5 with 4.2 and 5.2 as legitimate by unnecessary actions.

Response

Figure 3, a graph of illegal or ineffective actions, shows the responses on a country or block basis. Two reminders may be in order - firstly this distribution is by certificate issuing country not nationality. If a result is to be considered a reflection on the country, it is one of education and examination system, not necessarily national characteristic. Secondly 'illegal' actions are those chosen which violate the dictates of the Colregs and 'ineffective' actions are those which, though not illegal, do not solve but merely postpone the problem, ie, opting for own ship and target to slow down.

At first sight, the UK would appear to score best in this scenario - not that 38 per cent choosing actions not in accordance with Rules can be cause for congratulation. The interesting aspect here is the proportion of ineffective solutions to the illegal is roughly 20 per cent to 25 per cent for the UK, Philippines and the Commonwealth, whereas the rest are a lot fewer. As was mentioned in the last article on Scenario 2, opting for slowing down is likely more often than not to be a 'cop out', solving the problem by slowing down, thereby doing nothing illegal but possibly attempting to disguise one's ignorance of the correct action required. What is the significance of this variance of response? Could it be that some training regimes encourage a sense of pragmatism towards the Rules, or is it yet another a symptom of the self-preservation suggested in the October feature?

The question mark is further emphasised if we analyse these results from a slightly different perspective. Figure 4 shows the results if they are analysed purely from the basis of correct action of own ship, further dissected into positive and non-positive actions. 'Positive' in this case means an alteration to starboard in strict accordance with Rule 19(d)(i). 'Non-positive' includes slowing or stopping own ship, not illegal but suggesting an imperfect understanding of the rule.

On this basis, the UK response shows an even stronger tendency to do nothing illegal but at the same time demonstrating an apparent high level misunderstanding of the rule.

To sum up Rule 19, like Rule 8, despite being part of the Colregs for some decades still remains a mystery to a significant number of the world's seafarers. It is not surprising therefore, that such a high proportion of misunderstanding and non-compliance should result in those remaining, who do know the Colregs, sometimes finding themselves forced into non-compliant manoeuvres, purely as a prudent response to the chaos around them.

The summing up of the legitimate actions in Scenario 2 {Seaways October 2003) failed to include the option of the own ship slowing or stopping. The last paragraph under the heading Scenario 2 (page 8) should read:

'This equates to 2.2, 2.4, 2.5, and may also legitimately include 4.2, and 5.2, on the answer code as described in the August Colregs feature in Seaways.'

My apologies if this omission has created any confusion as to the correct response to this situation as defined in the Colregs. I would ask all those interested to refer to the full report of the survey contained in the Nautical Institute website. The report gives a more thorough analysis of the scenario than is possible to include in an article such as this.