Forum: The Racing Rules of Sailing
21.3 - Reversing ambiguity
Massimo Henderson
Nationality: Australia
Certifications:
- Regional Umpire
- Club Judge
0
Hi there,
I have recently being doing some research about 21.3 and reversing.
Rule 21.3 states:
“A boat moving astern, or sideways to windward, through the water by backing a sail shall keep clear of one that is not.”
This part of the rule is fairly straightforward in a basic sense, but upon delving further I realise there is some ambiguity. The word “by” is defined according to the dictionary as
“indicating the means of achieving something.”
So the first question is that let’s say a boat reversed by backing their boom, but then stopped backing their sail and continued moving astern. Does this qualify as “by backing a sail,” considering that they’re no longer doing it? If another boat was to begin moving astern without backing a sail then 21.3 would not apply. But what is stopping a laser in heavy wind from cranking their vang on (which will cause the boat to move astern rather quickly) and just drifting back through a pack to an advantageous position. They have not done the physical action of backing the sail, it is just the effect of the wind. This seems to be against the whole idea of 21.3.
The second question is around the preamble to 21 and 22, which states:
“When rule 21 or 22 applies between two boats, Section A rules do not.”
So let’s say two boats are going backwards by backing a sail, and rule 21.3 applies to both. Is that “between?” My interpretation previously was that as soon as both boats begin backing and moving astern then normal ROW rules apply between them, but 21.3 to anyone else . So if 21.3 applied between them, then no rules apply, which can’t really happen. So therefor 21.3 cannot apply between boats moving astern through backing?
This is a subject that is misinterpreted a lot from sailors so I’m wondering about how to clarify.
Thanks :)
Comments
[You must be signed in to add a comment]
Looking at the wording I'd both boats back the sail the usual rules do apply.
"shall keep clear of one that is not"..
Rule 22.3 requires a boat moving astern by backing a sail to keep clear of one that is not. Although Y is no longer backing her sail, she is moving astern because she backed her sail, and is still subject to rule 22.3. Y fails to keep clear and breaks rule 22.3.
I'm aware that TR Calls are not authoritative for MR, but I think the logic is persuasive
Thus shouldn't 13 apply and as they are both tacking then : "the one on the other's port side or the one astern shall keep clear"
Sure, such a boat could be tacking, as you say. In fact, they could both be tacking, in which case rule 13 wouldn't apply between them and we have to go back to rule 11 or 12 (or maybe 10, though that sounds like one of them really screwed up the backing maneuver). BTW, you can easily back a dinghy up without passing head to wind -- just go up to almost HTW and push the main out to leeward while pulling the tiller to windward until the boat stops, then reverse the helm to back up and get onto a close-hauled course. If you've got any real way on, the dinghy will first crab to starboard before it stops. That's a great way to open up a hole to leeward of you while stopping the boat, when you've just come into the lineup. But if you do that, be sure to keep clear of the boat to windward, and remember, rule 17 will apply to you after the starting signal!
> If two boats are subject to this rule at the same time, the one on the other's port side or the one astern shall keep clear.
So no need to fall back onto other rules, it is all in 13.
A boat that is near to HTW and then has the wind blow on the other side of their main sail has surely pass through HTW and is thus tacking!
Otherwise how are we meant to determine which side of the hull the wind is blowing (probably both when near to HTW)?
So a boat with the boom pushed out to leeward is sailing by the lee albeit with the wind on a different side of the sail to usual.
Thus leeward is defined by "the side on which her mainsail lies", and as the boom just changed sides, so the windward side just because the leeward side and the boat passed through HTW by definition.
I think this is a reasonable interpretation as it results in a clear answer as who should keep clear (clear astern and to port). However, I have no idea how a boat clear astern is going to keep clear of a boat going faster backwards into them.
cheers
Slowing by pushing the boom hard to leeward (to the port side) is not by the lee since the flow is from mast to leech.
I would say that a main forcibly held against the wind and thus back-winded is not laying on that side … it’s being held on that side. One needs to go back to determining the side of the boat that is away from the wind.
Sailing by the Lee was done to death in this thread https://www.racingrulesofsailing.org/posts/1156-sailing-by-the-lee
The consensus on that thread was that holding the boom out with the sail backed is not sailing by the lee. So I'm this case it doesn't constitute a tack when sailing backwards.
So any of the rules 10, 11, 12 or 13 may apply to two boats sailing backwards.
But I really think the wind has to be coming from astern for a boat to be sailing by the lee.
When the boat is pointing upwind the tack she on is resolved by the 'is or, when she is head to wind, was' wording in the first sentence of the Definition.