Rule 19.2(c) "at the moment the overlap begins, there is not room"
While boats are passing a continuing obstruction, if a boat that was clear astern and required to keep clear becomes overlapped between the other boat and the obstruction and, at the moment the overlap begins, there is not room for her to pass between them, she is not entitled to room under rule 19.2(b). While the boats remain overlapped, she shall keep clear and rules 10 and 11 do not apply.
Two boats are sailing downwind between an island (0.4km x0.4km) and a series of steel mooring pylons extending from the island that are together a continuing obstruction (able to be seen in satellite view near the coordinates below) and a shore. The wind is blowing parallel to the shore. The boats are sailing both on starboard tack with booms out at about 75 degrees from the centreline with wind coming from over the starboard rear quarter. They are headed towards the island as they are sailing the angles downwind rather than straight down the channel on a 180 degree to the wind run, but are 500m away from the shallows around the island. If the bigger, deeper draft, faster boat clear astern overlaps on the island (starboard) side of the slower boat 450m from the island but the wind drops a lot and the bigger boat cannot get past before the bigger boat gets to it's shallows (ie the deeper draft prevents it from going in as close as the smaller boat), does the bigger boat have any rights? Does it matter that at the time the bigger boat established its overlap and given the wind strength at that time, the bigger boat would have easily got in front of the smaller boat and gybed and crossed in front of it before reaching the shallows? Does it matter that if, at the time the overlap commenced, an extension was drawn along each boat's keel through the bow and to the island, both extensions would have hit the island (ie both boats would, if they held their course, have hit the island eventually, albeit at different times and places and depths. (-33.853414, 151.164230 and the boats are headed NNW towards Spectacle island, coming from near Drummoyne Sailing Club.)
If (at -33.850410, 151.163036) as the island begins the boats are sailing NW directly down the channel parallel to the shore on starboard and the front boat sees the boat clear astern approaching to overtake to windward/starboard and heads up so that it is now pointing to the island and the bigger boat still tries to overtake and then establishes an overlap but then is caught out by decreasing depth so it doesn't get past before getting to the edge of unsafe shallow water does it have any rights? In this case the overlap was established while extensions of the keel line of both boats pointed at the island.
What if the overlap was established while both boats were on course to sail past the island but the leeward boat afterwards began luffing the windward boat up towards the island? In this case extensions of the keel line at the time the overlap was established would both have missed the island. (I think in this case there was room and the leeward boat has to stop luffing and give room)
These situations occur in club racing of 3 clubs that sail in these waters.
Created: 17-Nov-09 05:20
While boats are passing a continuing obstruction,
Do you consider boats approaching from 450M from the Island to be passing a continuing obstruction or are they approaching a continuing obstruction? At what point does the island become an ?
A definition of may help. What was the length of the boat(s) in question?
I get surprised a lot when I'm confused by a rule an then find possible answers in the definitions. I rarely if ever read them because I always know what I mean when I use the words. Hope this helps as it shows the thought process I went through when I read the post.
- I see you're up late answering forum posts. I'm in South Korea today - slow afternoon between customer meetings.
19 and the Definitions do not specify the answer.
If ROW leeward is not yet required to choose a side, how can she be obligated to let the big boat take the same side? 19.2(b)
The definition refers to an object a single boat would have to steer around.
If the definition means the two of them jointly must change course substantially, then:
.
In your first case, as they approach, 19.2(b) would govern, not 2(c).
19.2(c) does not apply in this case, as big boat did not establish overlap "while passing a continuing obstruction." The overlap already existed.
Only 19.2(a) and (b) apply.
In your second case, 19.2(c) applies. and turns off ROW's luffing rights. 11
ROW must bear off and give room.
This is not the situation, at least in the UK thanks to the RYA Case which clarifies the situation as follows "The test to determine whether a boat establishing an inside overlap at a continuing obstruction is entitled to room requires the position of the outside boat to be frozen, but the positions of other boats in the vicinity are not frozen and must be moved forward in their same relative positions." In other words you more or less take an overhead snap shot of the situation when the overlap starts and if there is room (with the outside boat frozen in position) for the inside boat to pass between her and the obstruction then the inside boat is entitled to room to do so even if as the outside boat moves forward that room disappears and the outside boat has to alter course to give room.
In all the cases quoted the inside deep draft boat has room (using the RYA test) at the moment the overlap begins to pass between the outer shallow draft boat and the obstruction and is therefore entitled to do so. The room she is entitled to is to sail along the depth contour that is safe for her as this would be the limit of the obstruction as far as she is concerned.
I realise that RYA cases do not govern other MNAs and I would be interested to see if any similar cases exist elsewhere.
Thanks for the RYA Case reference. That is EXACTLY how I've explained it to others in that it's not a converging course projection for the room calc, but an "at the moment the overlap begins" calc .. and a moment is a picture, not a movie.
Going back to my previous continuing obstruction thread and pic .. you can see that is also an frequent issue every Wed night as boats squeeze to windward along the piers to the south to the finish.
Like you said, the RYA case doesn't govern, but a good explaination is a good explaination even if it comes from across the pond ;-)
PS, I think I should add that given the scenario, that the obstruction is an unseen underwater contour and that one boat is not responsible for knowing the draft of its competitor, .. and that the depth margin is "squishy" in terms of each skipper's reasonable determination. Therefore, the deeper, bigger, inside boat would have the benefit of the doubt in the scenario you've put forward as a boat's width pales in comparison to the resolution and detail of where that depth-line is.
On the other hand, if this was along a visible, well-defined bulkhead or seawall with good depth to the edge, these distictions can be more easily decerned if the width to pass was available at the moment of the overlap and thus the gap-closing boat would have more of a defense.
You might just gybe away.
Hi Bill and Angelo,
Thanks for the explanation that it is a snapshot or picture for the outside boat, not a movie, that the emphasis for the outside boat is its position at the moment.the overlap is established, not on any projection of it's course.
My interest in these situations is as a member of a protest committee panel of a club in the area.
Hi Paul Z
Do you agree that the situation is a picture/snapshot as far as the outside boat is concerned?
Mark Pryke an international judge in Australia also emphasises good decision making on the water, what you might call percentage sailing, evaluating the downsides of a tactic as well as the upside eg on approaching a mark (with a likely line of starboard tackers also approaching at the same time) on port tack.
Thanks all.
This may be born out with the discussion of a boat fixed in place at the time of overlap and I think it has much of the same effect. Its not whether a boat can keep you from passing clearly as much as is there room at the time of overlap.
The counter example is when you are sailing 6M from the pier but your spin pole 3M from the docks and a boat sticks his nose inside your transom while his pole is CM off the seawall and then realises that he's about to run through your spinnaker (This is from experience).
Interesting discussion,
The distance chosen was possible in the geographic circumstances referred to but was chosen to highlight the idea that it was about projecting a line along the keel of the outide boat and a distance that normally allowed a fast boat to overtake between the slow baot and teh obstruction then gybe in front of the slower outside boat.
What seems to be the answer now is that the rule would only apply in very limited circumstances and very close to the continuing obstruction.
In fact using the "picture, not a movie" argument referred to above if there was a boat length to a wharf sticking out in front of the boats sailing along a shore then, provided at the moment the overlap was established the bow of the outside boat was at least a boat length from that wharf, the inside boat would have room as, if the outside boat was frozen with its bow at one boat length before the wharf, the inside boat could sail past it and gybe and come back out from the shore between the wharf and the bow of the outside boat.
I find that as unpalatable result as using a projection of courses for 400 metres as it suggests that a situation of marginal safety is quite acceptable, but it seems a necessary implication of the "picture not movie" approach.
I am more interested in the situation where boats are sailing the angles downwind to keep the boom roughly perpendicular to the wind for maximum apparent sail area (with the jib poled outon a long whisker pole) and are approaching the obstruction at an angle. What is the limit of obtaining an overlap in relation to closeness to the unsafe bottom contour. It seems from the picture/movie analogy that the overlap can be established with the bow only about a boat length from the unsafe bottom contour. This is seems consistent with the Rose explanation where Anne only allows a gap a bit wider than a boat with its boom out between her and the unsafe contour.
Thanks all.