Showing posts with label keep clear. Show all posts
Showing posts with label keep clear. Show all posts

Tuesday, June 30, 2015

IRPCAS? I think not.

The Preamble to Part 2 of the Racing Rules of Sailing (RRS) contains an interesting provision: “If the sailing instructions so state, the rules of Part 2 are replaced by the right-of-way rules of the IRPCAS or by government right-of-way rules.” (IRPCAS stands for International Regulations for Preventing Collisions at Sea, usually called the COLREGS. The US Coast Guard publication containing these rules can be found here.)

The rules of Part 2 govern the conduct of racing sailboats when they meet, including right of way, mark-room, and room at obstructions. In theory, regatta organizers could throw out those rules and substitute the IRPCAS rules of the road for their entire regatta, but I've never heard of this being done. The only situation I've heard of in which IRPCAS rules replace the rules of Part 2 is for long-distance races, and even then, only during hours of darkness. But even in that limited application, IRPCAS rules of the road don't really work for sailboats racing each other.  

The idea behind invoking IRPCAS rules in long-distance races is that those rules rules don't allow close maneuvering, so the boats would be safer than they are under the rules of Part 2. But I have the feeling that many of the folks who write sailing instructions replacing RRS Part 2 with IRPCAS rules of the road really don't understand what they're doing. Here are a few facts about the IRPCAS rules as they would apply to sailboats racing:
  1. IRPCAS rules apply to any pair of sailing boats in sight of each other (IRPCAS Rule 11). That's a long way apart – at least 5 miles in most cases. Technically, the RRS also apply to boats far from each other, but the rules of Part 2 only require boats to take action when they are in close proximity.  IRPCAS rules require boats to take action as soon as it appears that, on their current courses, the boats might collide; at that time they could be miles apart.
  1. Under IRPCAS all vessels are required to maintain lookouts, “by sight and hearing”, and vessels equipped with radar must use it (IRPCAS Rules 5, 7(b)). In fog or other reduced visibility, vessels must slow down to “a safe speed adapted to the prevailing circumstances and conditions of reduced visibility” (IRPCAS Rule 19). Such conditions include background lights ashore at night, as well as fog and rain (IRPCAS Rule 6(a)).
  1. In terms of maneuvering, a give-way vessel must “take early and substantial action to keep well clear” (IRPCAS Rule 16), and a stand-on vessel must maintain her course and speed (IRPCAS Rule 17(a)) except to avoid imminent collision (IRPCAS Rule 17(b)). If there is any possibility of danger of collision, give-way vessels must act as if there is such danger, and take appropriate action (IRPCAS Rule 7(a)).
  1. IRPCAS does not assign right of way between two boats under sail the same way as do the RRS. Under both sets of rules, port-tack boats must keep clear of starboard-tack boats and windward boats must keep clear of leeward boats, but there is one big difference: RRS 11 only requires a boat clear astern to keep clear of a boat clear ahead if the two boats are on the same tack, while IRPCAS requires the boat astern (the “overtaking boat”) to keep clear regardless of what tacks the boats are on. Further, in that situation if the boat ahead changes course, the overtaking boat must continue to keep clear even if the boats are now in a crossing situation (IRPCAS Rule 13(d)). For example, if both boats are on starboard tack to begin with, and the boat ahead tacks onto port and crosses the other boat, the boat that was clear astern must continue to keep clear even though she is on starboard tack and the other boat is now on port tack!
  1. Of course, the IRPCAS have no rules equivalent to the rules of Sections B and C of Part 2, because the IRPCAS rules do not envision that vessels will come close enough to require “room” or “mark-room”.  (There is also no equivalent to the rules of Section D, but those rules are not likely to apply to boats racing offshore at night.)
The fact that IRPCAS and RRS assign right of way differently should make us wonder how much safer boats will be, racing under IRPCAS.  Racing sailors may or may not know the racing rules by heart, but most of them know and understand the game defined by those rules. On the other hand, most are totally unfamiliar with the game defined by IRPCAS. How much safer can it be to suddenly drop a fleet of racing sailors into that new brier patch?

As a full-time cruiser with tens of thousands of miles of passages under my keel, I'm pretty familiar with IRPCAS, and in my opinion there's no way anybody could reasonably race sailboats under the IRPCAS rules. On our cruising boat, if we see a vessel approaching on a nearly constant bearing, we hail her on VHF Channel 16 when she's at least a mile away. If she responds, we negotiate the crossing (“Request permission to cross ahead of you,” or “We will slow and pass astern of you,” etc.). If she doesn't respond and we are the give-way vessel, we immediately take avoiding action – even though the other vessel is still almost a mile away! IRPCAS requires that such action be substantial enough so that it is “readily apparent” from the other boat (IRPCAS Rule 8(b)), so slowing from 6 knots to 5.8 knots or changing course by 5 degrees won't satisfy the requirement, even if such an action is all that's needed to avoid the danger of collision.

If we are racing against each other with you on port tack and me on starboard, would you negotiate with me on VHF radio regarding which of us should change course or (gasp!) reduce speed? If you're the keep-clear boat, would you change course substantially (basically, tack or bear off by 20 degrees or so) while we're still, say, a mile apart, as required by IRPCAS? I think not; but if the sailing instructions mandate IRPCAS, I can protest you if you don't.

While the IRPCAS requirements on give-way vessels seem extreme, the limitations imposed on stand-on vessels are even more onerous. IRPCAS Rule 17 says that a stand-on vessel “shall keep her course and speed” when another vessel is keeping out of her way. Suppose X and Y, both 50-foot boats, are beating to windward on the same tack with X ahead and to leeward of Y. Because Y is the “overtaking vessel”, she is required to keep out of X's way, which she is easily doing. Now suppose X discovers that she's entering an adverse current or big header and decides to tack. That means changing course toward Y, and if X's new course puts her on a more or less constant bearing from Y's point of view, then when X tacked she broke IRPCAS Rule 17. If the boats are racing under IRPCAS, Y may protest and get X disqualified, even if it takes little effort for Y to avoid X on her new course, or X tacks back when she is still several boatlengths away from Y.

Of course, if boats will round a mark or cross a finish line at night, all bets are off. IRPCAS is simply not set up to handle situations where vessels purposely put themselves in danger at full speed. It's hard to imagine a mark rounding or finishing scenario in which all boats within sight of each other don't break IRPCAS, one way or another. Protests galore!

So, if IRPCAS rules aren't the solution, what can be done to make night racing safe? My idea is to keep the RRS, including Part 2, but establish an understanding of what it means to keep clear, that ensures greater distances between boats.

The first part of the definition “Keep Clear” in the RRS says, “A boat keeps clear of a right-of-way boat … if the right-of-way boat can sail her course with no need to take avoiding action ...”. Organizers can't change that definition (see RRS 86.1) but the expression “need to take avoiding action” is not a defined term in the RRS and depends on the prevailing conditions. In daylight, even maxi yachts are accustomed to sailing within a boatlength or less of each other at full speed, but at night in the open ocean, surely a crossing at speed with only a length or less between the boats will have both crews terrified, and the right-of-way boat might well think she needs to take avoiding action.

So I suggest a provision in the Notice of Race and Sailing Instructions, saying something like:

In the case of a protest, the jury will make the following rebuttable presumption: Between sunset and sunrise, if boats come within two of the longer boat's overall length of each other, the right-of-way boat needs to take avoiding action.”

Obviously the organizers could take an even stronger position and drop the word “rebuttable”, but I think that's unwise. “Rebuttable presumption” means that the jury makes that presumption but upon strong enough evidence that it is not true they may drop the presumption. For example, if a port-tack boat crosses a length and a half behind a starboard-tack boat, the starboard-tack boat wouldn't feel she needs to take any action to avoid the other boat because the boats are, at that point, sailing away from each other.  In that case, the jury is free to drop the presumption.

Note that if the jury keeps the presumption, rules requiring the right-of-way boat to give the other boat “room to keep clear” are broken if the actions of the right-of-way boat brings her within two lengths of the other boat. For example, if the right-of-way boat changes course so as to bring the boats within two lengths of each other, she breaks RRS 16.1 because the other boat needs to take avoiding action, under the presumption in the sailing instructions. By the same reasoning, an overtaking boat on the same tack breaks rule 15 if she establishes a leeward overlap at night within two of the longer boat's lengths. This puts more of a burden on such a boat than the “proper course” restriction of rule 17.

Overall, my advice to organizers of long offshore races is, stay away from IRPCAS as a replacement for the rules of Part 2, and be sure to communicate clearly to competitors that the distance needed to keep clear at night is substantially greater than the distance needed during daylight.

Tuesday, November 5, 2013

Hunting and Trapping in Fleet Racing -- Q&A 2013 034

ISAF recently published Q&A 2013 034, and I think they got it wrong.

The question (which is a little hard to find in the Q&A) is, essentially:

If a boat A acquires right of way or changes course in such a way that a keep-clear boat B momentarily cannot keep clear, and then A immediately acts to give B room to keep clear, should one or both boats be penalized?

The answer they give is, essentially:

Not unless there was contact or B had to maneuver in an unseamanlike way.

This brings fleet racing in line with match and team racing, where there are calls saying that if a right-of-way boat ultimately gives the other boat room to keep clear and there's no contact, then the incident should be green-flagged (no penalty). These calls, and the Q&A, say, in effect, “No harm, no foul.”

Or maybe more accurately, “All's well that ends well.”

This basic idea has been around in match and team racing for a number of years. As an active match and team race umpire, I understand the motivation for this Q&A, and maybe even like it in some circumstances, because a “no harm, no foul” attitude reduces needless protests for situations where, ultimately, nothing happened.

Consider, for example, two boats maneuvering two minutes before the start. A and B are headed off to the right, beyond the race committee boat, with A two boatlengths to leeward and bows-even with B. A decides to go back to the line, so she luffs and tacks, with her helm hard over. At the moment she completes her tack, if she were to center her helm and go straight she'd run smack into B's starboard quarter; but of course, she doesn't do that. She keeps her helm over and ends up on a reciprocal course to B. Boat B never changes course, because she knows that A is simply “going back” and will get out of this situation with no harm to either boat; and in my experience B never protests. This kind of situation happens all the time, and Q&A 2013 034 says it's OK – even if B were to protest, the protest should be disallowed; and that's a good thing.

My problem is, whether this is a good idea or not, you can't get to the Q&A's conclusion from the rules. In other words, I understand the theorem – I just don't understand the proof.

The Q&A poses 4 incidents. Each of the situations is a little different from the other, and although the Q&A takes them all on at once, we'll look at them one at a time. Let's take the first scenario:

The situation 1 description, from the Q&A, is as follows:

A tacks onto starboard tack so close to B on port tack that A cannot sail straight ahead without hitting B, and B cannot avoid a collision by maneuvering promptly in a seamanlike way. A then immediately changes course to give B room to keep clear. A protests B under rule 10 and B protests A under rule 15.
 
Note the words, “A … changes course to give B room to keep clear.” This seems to require that we know A's motives, which we don't. Just above this statement, the description says, “A cannot sail straight ahead without hitting B”, so why doesn't the subsequent phrase say, “A … changes course to avoid hitting B”, which is clearly true, regardless of any other motives?

The answer is, if they had said that, then one of the boats would have to be penalized, because of the definition of Keep Clear:

A boat keeps clear of a right-of-way boat 

     (a) if the right-of-way boat can sail her course with no need to take avoiding action and,

     (b) when the boats are overlapped, if the right-of-way boat can also change course in both
          directions without immediately making contact.


The Q&A quotes part (a) of this definition, which is clearly the applicable part in situation 1.

It seems to me that, according to both the diagram and the description, if A had held her course at position 2 she would have hit B. So A needed to take avoiding action at position 2. So B broke rule 10 at that point, and A broke rule 15 by not initially giving B room to keep clear. It was A's breach of rule 15 that compelled B to break rule 10, so penalize A and exonerate B (see rule 64.1(a)).

In situation 2, B on port tack is clearly crossing A on starboard tack. After B commits to crossing ahead of A, A dials up on B to a point where B is no longer keeping clear. A then immediately changes course to give B room to keep clear. A protests B under rule 10 and B protests A under rule 16.1. According to the Q&A, neither boat should be penalized. The diagram is below.


Putting aside the difficulty of getting to the Q&A's answer from the rules, this situation raises some other issues. In situation 1, B sees A's maneuver and is able to eventually keep clear. But in situation 2, B has committed to the cross before A hunts up at her, so B is like a deer caught in the headlights. (The match-race Call where the keep-clear boat is unable to respond to a course change by the right of way boat is commonly referred to as the "Bambi call".)  At position 2, B reasonably thinks she's going to be T-boned and there's nothing she can do about it. If her skipper isn't scared out of his mind, he should be.

In match racing, where boats are not required to take penalties for breaking rules and we couldn't care less about terrorizing competitors, A's behavior doesn't cause a problem. But in fleet racing, and even in team racing, where all of “Sportsmanship and the Rules” is in effect, it causes a big problem, at least for me. What B sees is that she didn't make the cross, and A had to bear off sharply to avoid her. B is not in a good position to judge A's course because her perspective is constantly changing, so she may well not be aware that A hunted up on her; and A's protest reinforces the assumption that A's bear-off was to avoid hitting B. By hunting up and then bearing off sharply, A is perpetrating a fraud in an effort to draw a foul. She hopes that B will take to heart her duties under “Sportsmanship and the Rules”, and take a penalty. In other words, A wants to punish B for being sportsmanlike. To my mind, whether or not either boat breaks a rule of Part 2, A's behavior here breaks rule 2, and the Q&A Panel should be ashamed of putting this situation in the Q&A.

Situation 3 raises yet another problem. In that situation, A establishes an overlap from clear astern on B. The overlap is so close to B that A cannot change course in both directions without making immediate contact with B. A then immediately changes course to give B room to keep clear. A protests B under rule 11 and B protests A under rule 15.
Here, part (b) of the definition Keep Clear comes into play. At position 2, according to the Q&A description and diagram, A cannot change course in both directions (in particular, she cannot luff up) without immediately making contact with B, so B fails to keep clear.

The interesting thing here is that rule 15 says, “When a boat acquires right of way, she shall initially give the other boat room to keep clear, unless she acquires right of way because of the other boat’s actions [emphasis added].” What could be more “initially” than the situation in position 2, where A has just established the leeward overlap? Rule 15 says nothing about “ultimately” or even “a little later”; so how does the Q&A Panel get around this word?

Situation 4 raises yet another issue. A and B are overlapped, with B as the windward boat. A luffs quickly, and before B can move away from A in a seamanlike way, the boats are so close that A cannot sail straight ahead without hitting B. A then immediately changes course, giving B room to keep clear. A protests B under rule 11 and B protests A under rule 16.1.

Unlike the other situations, this scenario frequently occurs in fleet racing, and not uncommonly results in protests. It's also one of the main scenarios the rules-writers were thinking of when we wrote rule 16.1 in the first place, back in the 90's. Rule 16.1 was a huge game change; the old rules said that A could “luff as she pleases”. When we wrote rule 16.1 we fully expected that if B could show that A luffed too fast for her to react, A would be disqualified under that rule. And now the Q&A Panel is saying, “Not so. As long as there's no contact, let A play her nasty little games.”

Which brings us to the final interesting feature of the Q&A. What does contact have to do with this issue? There's no mention of contact in any of the rules involved here (rules 10, 11, 15 and 16.1), and the only mention of the word “contact” in the definition of Keep Clear clearly deals with an event in the future. In other words, when there's contact, the keep-clear boat was already breaking a right-of-way rule before that contact. ISAF Case 88 says, “‘Keep clear’ means something more than ‘avoid contact’; otherwise the rule would contain those or similar words,” and of course, that Case is right. It doesn't really matter whether there is contact; if the right-of-way needs to take avoiding action or cannot change course in both directions without making contact, then the other boat is failing to keep clear.

All in all, I think the Q&A Panel got it wrong, this time.