Monday, December 01, 2008

Both Leeward Both Starboard - Bigger Crunch

Here is a variation of the puzzle posed in Both Leeward and Both Starboard. Basically the same situation as before except that each of the two starboard boats makes contact with the windward side of the other (as windward is defined for each boat in the Definitions in the Racing Rules.)

One imagines that there would be a good deal more shouting in this situation as is it is clear from position 1 that the boats are on a collision course. Red would of course claim that Blue was on her (Red's) windward side in all 3 positions. However Blue would claim that, when the collision occurs, Red was on her (Blue's) windward side and that Red was therefore obliged to keep clear.

So does this differ in principle from the previous example? When Red passed to the windward side of Blue (as defined in the Definitions for Blue, a boat sailing be the lee) was Red obliged to start keeping clear? If neither boat changed course should both be DSQ'd for failing to keep clear under Rule 11?


merrifie said...

In principle, I think this is no different than the previous situation. Blue is the 'give way' boat and that doesn't change until the obligation to keep clear is fulfilled. How can blue hold course and then claim at the last second that it now had rights?

Anonymous said...

M Sqared asks, "How can blue hold course and then claim at the last second that it now had rights?"

Well that kind of situation happens all the time. Just one example. Boat A approaches a start line later than Boat B that is already in position just below the line and luffing.

B is clear ahead of A, so A is the 'give way' boat... until the moment that A establishes a leeward overlap on B. Then B becomes the 'give way' boat and must begin keeping clear of A. Sure, B has some protection under Rule 15 which says that A must "initially" give B room to keep clear. But B does have to start keeping clear.

But my point is that there are many situations on the race course when the relative rights of two boats instantly switch (subject only to that provision in Rule 15).

My question here is, "Does blue become 'right of way' boat at some point?" Because, if so, Red has to start taking action to keep clear at that point.

merrifie said...

But in your example, 'A' meets its obligation to keep clear and then establishes leeward rights. My question was not a generic one that applies to all situations on the course. Certainly things change and sometimes rapidly. In the situation described in the post, neither blue or red change course. Blue never met its obligation to keep clear.

David said...

Steve Colgate sez: "The reason for the contradiction in the case of sailing by the lee is that the right-of-way rules define the leeward side as the side over which the main boom is carried. . . Since the boom is far more visible than the wind, it is used for the legal definition . . .Of two boats, one beating to windward and one running downwind, the wind hits the latter first so it is the windward boat. The other is the leeward boat." -- 'Fundamentals of Sailing, Cruising, and Racing'

If Steve is right about this, blue is the windward boat and must keep clear.

Anonymous said...

Hmmm. That's interesting David. But I would be interested to see the full context of Steve Colgate's statement.

I know other commentaries on the Racing Rules make a similar statement about a beating boat and a running boat saying that the running boat is treated as the windward boat. It's a great rule of thumb and certainly true most of the time. The question is whether this rather weird example is an exception to that "rule of thumb" or not.

I don't see anywhere in the Racing Rules or Definitions where "windward" is defined as "the boat that the wind hits first". So with the greatest respect to Steve I'm not sure that this argument can be used in this example.

David said...

Yeah, I wasn't sure that helped much either. You can find the full text by doing a Google book search.

Here's another thought. Are the boats technically overlapped? If not, then rule 11 doesn't apply and we have to go to rule 12. Could we make the case that blue is clear astern (relative to the race course--I know, I'm making up definitions here)and therefore must keep clear?

Hell, I'm not sure that makes sense either. Nice one, Tillerman. I guess Nick Rose doesn't subscribe to you blog?

Anonymous said...

They are technically overlapped, because the definition of overlapped is when niether is clear astern of the other.
When Blue saw Red on the side where her Blue's boom was, and not behind Blue's transom, Blue should have known to keep clear, meaning don't make Red take avoiding action. I'm with M².

Maybe instead of deciding whether blue got rights at the last second, it is enough to agree that blue had responsibility to keep clear until the last second.

The only hope for Blue is to argue that she kept clear while during the time she had that responsibility, because avoiding action became necessary only after the boats were starbord of each other. (So both broke rule 14 only.) I do not see much hope for that argument.

Amando Estela said...

Exactly the same. The boat closehauled is all the time RoW and the other one has to keep clear.

If by any (fantastic) reason there is a transfer of RoW just before the collision then R15 kicks in.

Tim Coleman said...

This kinda happened to me. Not quite as your drawing but close enough. Check it out at...

The O'Sheas said...

They are both described as "her." Do you have a problem with women?

Anonymous said...

Yes. Don't we all?

Christy ~ Central Air said...

Hey now. Easy, boys.

Colgate's downwind boat = windward boat explanation seems plausible to me, but then again, I was the chick who couldn't even understand the original scenario in T-man's previous post.

Anonymous said...

Let's face it, RRS 11 is written on the incorrect assumption that if one boat is to windward the other boat will be to leeward, according to the definitions. As we see, this assumption is not correct in the by the lee situation described.

From Red's point of view, under rule 11, it doesn't matter if Red is to windward or to leeward of Blue. All that matters is Blue's position relative to Red, that is, whether Blue is to windward or to leeward of Red.

In the previous scenario when Blue crossed ahead of Red, looking from Red, Blue was then to leeward of Red, on the same tack, so Red had to keep clear, simple rule 11. Fortunately, looking from Blue, Red was also then to leeward of Blue, on the same tack so Blue had to keep clear, likewise simple rule 11. Each is obliged to keep clear of the other.

In this case, where Blue does not cross ahead of Red, looking from Red, Blue is to windward of Red on same tack, so Red has no obligation to Blue under rule 11. Sadly, looking from Blue, Red also is now to windward of Blue, on the same tack, so Blue has no obligation to Red under rule 11 either. NEITHER boat is obliged, under rule 11 to keep clear of the other, thus, according to the preamble to Section A, NEITHER boat is a right of way boat.

Neither boat acquires right of way in the second scenario, so rule 15 never applies.

So the only thing we can fall back on is rule 14. Each boat must avoid contact with the other if reasonably possible.

But rule 14 has some teeth here. If reasonably avoidable contact occurs, even if there is no damage or injury, then both boats break rule 14, and neither boat is protected by rule 14(b), and can and should be penalised.

Phew. Tough one.


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