Dart 15 Forums

Anybody who has ever attended a Sprint 15 open meeting or a championships will have come across the inverted 'P' course. This is something we slip into the sailing instructions, and we have come to live with it.

But what is its use, and why do we have it?

Your observations would be very welcome. I have added a poll. My vote is a NO simply because I don't understand it!

Andrew.

Hi Andrew,

As far as I am aware, I think that the point of the inverted 'P' course is that, on each lap, it tests the skills of the competitors on all points of sailing (depending on the position of the 'wing' mark and the reaching angles created). It gives similar points of sailing to 'sausage, triangle, sausage, etc.' but the course is the same for each lap. I realise that the same thing can be achieved with a trapezium course which gives similar legs.

I don't understand why you don't understand it.

Ian (Yorkshire Dales S.C.)

Hi Andrew,

I join you in a dislike for this course - albeit for a different reason. It is the course I've seen the most accidents on!

When I've sailed it, it has tended to be amongst large nos. of boats & therefore with helms of differing ability in both rule knowledge & boat handling. My dislike for it orignates from the likelyhood of the crossing of boats on differing tacks at/around the leeward marks. Here I have seen rules being 'overlooked' & coming togethers as a result of inexperience/skill.

I appreciate some like the variety of an alternate course at an event but I'm also not keen on what often results which is a lot more downwind sailing with less fast reaching.

That said, I'm happy to go with the flow as to what courses we use at Nationals but I'd hate to think we have put off some of our members from racing & attending future events following any previous bad experiences.

Of course Andrew, with the 2008 Nats at your club, your preferences may count.......!

Keith

well we used the inverse p at the nationals and open meeting sometimes. i don't like it because sometimes there is two leeward marks which requires thought as to which one to round. also i remember erling charging in to the wing mark with no water on starboard, but we couldnt gybe onto port so he went straight through.

Hi Guys.

The reason why we have the inverse 'P' course is variety.

As a fleet we do not like the old fasioned Olympic Course (triangle, sausage, etc) as the reaches are too broad and the sausage involves a long run which is not very tactical with just one sail when you can go straight downwind. It is also less good for the heavyweights who tend to wallow on the downwind leg. We also do not like upwind-downwind courses which are popular with the asymmetric classes for the same reason.

The square or trapezoidal course is universally popular because we get tighter reaches and less downwind (for the trapezoidal).

The inverse 'P' course has exactly the same advantages as a trapezoidal course as it offers tighter reaches than a trangle and a lower proportion of running than an Olympic. So it offers us an alternative course. It would be a boring life if we did squares or trapezoidal courses all the time.

At the Nationals we generally use a downwind gate with the inverse 'P' course and also prevent the competitors from sailing through the start/finish line in the downwind direction. This presents the sailors with 2 tactical alternatives (which end of the line to go around and which of the 2 leeward marks to round). This tends to be a test of skill and judgement and breaks up the procession on a well set course.

The one disadvantage is that the region between the start finsh line and the 2 leeward marks can get busy/ congested and we have had some collisions, especially down at the novice end of the fleet. This has been worst when there has been a strong wind (when things happen fast) and we have been tight for space (e.g. at Grafham in 2003). For this reason for the last couple of years we have mostly used the square course when the wind was strong and we have not been too constrained for space.

At Netley I came to the conclusion that we should have a 3rd course option for sailing in a narrow estuary which would change the order in which the legs of an inverse 'P' course were sailed such that the course becomes a 'd' course. Thus we would beat to mark 1, run to mark 2, reach to the wing mark 3, reach to the leeward mark 4 and then beat through the line. The advantage of this would have been that we would have had better reaching angles on day 3 at Netley where the first reach of an inverse 'P' course was very broad and long. It has a couple of disadvantages - the boats going onto the run at the windward mark impede those approaching he mark on port tack and there is not the option of a downwind gate. I do not plan to add this option to the sailing instructions until we next sail in a congested piece of water.
Cheers
Bob

Andrew,
I presume you’re asking this question with a view to next year’s Nationals?
So I presume that you mean the inverse P course with the gate at the end, that competitors can choose which way to round as we’ve used at recent Nationals?

My personal opinion on the way that it’s been used most years is that it’s been a formula for collisions and I haven't liked it. (Yes, I've had collisions)!
For those at the front, with a shrewd tactical brain and a trust in their fellows, that they all know the rules (and will stick to them), then it can be an opportunity to make a gain. But for a lot of less experienced competitors it becomes more of a collision avoidance excercise than a tactical opportunity.

But,
I understand Bob’s point about variety of courses and I accept that it can introduce the possibility of making a tactical judgement to make a gain. All that’s good, but in practice it hasn’t often worked.

The biggest problem that we’ve had has been the inability of race officers to lay the course well.
Sometimes that’s because of the stretch of water is too tight, at Netley for example, but more often it seems to be just not thought through properly.

The only National’s I can recall where it worked really well, was at Pwllheli, North Wales in 2005.
In that case the R/O set the 2 leeward marks a long way back from the committee boat and they were spaced some distance apart. That gave the fleet the opportunity to spread out and sort themselves out by the time the marks were reached, whilst still allowing for a tactical choice. It also meant that there was plenty of room to avoid boats crossing up and downwind. It worked well and added a genuine tactical choice.
But usually we seem to get the 2 leeward marks set about 50-100 yards from the committee boat and it lands up being too tight and congested with lots of uncertainty what to do, and then the inevitable bumping and barging.

I guess my verdict on this, is that it can work well, but only if the course is set well, and the stretch of water has room for it.

Regards
Gordon

Folks,

My view on this course is that its my least favorite course in the nationals. I'm fine with the trapezoids.

The problem is definately the gate I find that its too easy to be 'taken' to a mark that you don't want to goto because someone too leeward wants to go there leading to crash gybes which if you have someone too windward may mean a collision. Also when you cross one of the lines of boats approaching the finish line after rounding one of the marks on the run there is a huge scope for collision here, especially if you are in the mid or end fleet, at both Saundersfoot and Netley I had to stop to allow a boat(s) to cross ahead because I couldn't avoid them. The chaps who are in the lead won't have a problem with the course but in the mid fleet it can be chaos.

Why have the gate?

Now I admit to having a bit of a mental block about large fleet sailing meaning I don't sail well in them and fret too much about avoiding people and not sailing in the packs. Getting stuck in a piggy in the middle type situation is a nightmare! I like to finish the event with a boat in one piece and preferably not caused any damage to someone else and I know I'm not going to be walking off with the silverware.

Martin S.

I agree with Martin. The idea is great - give choice of tactical sailing. However once the first tranche of boats have rounded those in the middle are in great danger from virtually all directions- especially in higher winds.

To give a benefit in terms of variety as Bob suggests does require those setting the marks - and relation to the finish - to take quite a bit of care and if there are any significant wind shifts this can go to pot.

This is a problem where time on the water is restricted, like our limit of 3-4 hours tops. For clubs with short sailing times I believe the setting of the course takes too long.

A variation without the gate - a single mark to be rounded in a specific direction would remove some of the interest but potentially save a lot of damage - and risk - but would not overcome the issue of significant wind shift.

Steve W

Having done 5 nationals, I still do not understand the P course and why one way is better than the other, but I hope the penny will drop one day. Gordon is right that the Pwlheli nationals had a good P course by moving the buoys a large distance from the start/finish line. I think it is a tricky course to sail, but it improves seamenship and thats why we should keep it. It also ensures that I look the rules up before attending!

I have never liked the P course except like Gordon at Pwlheli when we had a top man setting the course. I am always amazed that a OOD will move buoys around between races because the wind has moved 5%, but will watch as all the boats go the same way in a P course instead of both ways and not change for the three races. At Carsington in September we did a course I think Ray called a B course and it was blowing hard and seemed to have everything good about racing.

Post deleted! I'll come back later.

Hi,

The inverted P course (why was it never called a 9 course?) is getting a lot of criticism. I've a lot to say, and some specific suggestions if you just want to read the last 4 main paragraphs!

I don't like are inverted P courses that have been poorly set, or turn out to be poor because the decision to use the inverted P course was taken without regard to the likely nature of the strength and shiftiness of the wind and variability of the tide over that part of the course between the start-finish line (SF) and the leeward gate (G). Even if the RO notices and resets the course between races I don't like the delay due to the number of marks to be reset.

To avoid being poorly set, it is critical to that the relative positions of P mark (the mark nearest upwind from SF), SF and G are set so that boats rounding the P mark have a genuine choice as to which way to go round SF, and boats approaching G have a genuine choice as to which mark to round to beat up to SF.

To achieve this, if you draw a line dead downwind from the P mark :

the outside edges of the committee boat and the pin mark of SF need to be equidistant from my imaginary line
AND
the SF needs to be at right-angles to my line
AND
the outside edges of the buoys of G need to be equidistant from my line
AND
G needs to be at right-angles to my line.
(Equidistant and at right-angles should be taken as close as practicable to these ideals - perfection is never possible!)

When there is real error in the positioning of these marks relative to the wind (/tide), most boats will take the same route and the downwind and upwind lines of boats will cross on just one side in the area between SF and G. (Exceptionally, if the wind backs or veers through around 90 degrees then it is possible that few boats will cross at all, and sometimes then upwind of SF - but a halfway good RO would then shorten course to limit use of a "silly" course, and reset marks for the next race!). If the marks are properly set relative to the wind the number of boats on each side having to cross should be roughly halved - there should be bigger gaps for crossing lines of boats and much less chance of collision.

ALSO the relative distances between the marks needs to be set.

A start-finish line is usually set wide enough so that boats aren't going to be limited in the area in which they must tack to cross the line and also avoid "crowding" when trying to pass through a short line, especially when finishing is involved. Given that boats are approaching G downwind, G should be at least as wide as the minimum sensible length of SF if they are not to be "crowded"! If gate G is narrow then I challenge even the most knowledgeable of helms to be clear ON THE WATER about when which boats have right of way and when which boats must keep clear AND how this changes as 2 "gaggles" of boats, each gaggle of 6 to 9 boats, approach, merge and pass through the gate, especially if the time for decision is short because of boatspeed in stronger winds. If you think this is straightforward, remember that some boats may become within 2 boat lengths of both gate marks, having just previously been within 2 boat lengths of just one of the marks, or even neither, before coming within 2 boat lengths of just one of the marks, and you may not know which mark any boat (including yourself!!!) is actually aiming to round until they reach G itself! And imagine how a gaggle of later helms encountering 2 recently capsized boats just to windward of a narrow gate would suffer a collective nightmare trying to change course and get past in the limited gaps available! Has Nick ever used the narrow leeward gate situation in one of his "off the water evening exercises" at the annual teach in? I hope a Protest is never the subject of a subsequent Appeal.......

So gate G should always be clearly more than 4 boat lengths wide, much more so in windy (especially gusty) conditions, so there should then be 2 separate gaggles of boats at each end of G - none of which could be within 2 boat lengths of both ends of the gate! Collisions due to boats taking an unexpected route at G, maybe with right of way, are also then much less likely.

There should also be a long distance between SF and G so that there is plenty of space for crossing boats to manoeuvre, rather than the space being compressed into another collision zone. I'd suggest a gap that would take at least 3 minutes to beat - eg as at Pwllheli. And to give upwind boats some flexibility of choice on when to tack for FS, the FS itself has to be quite long... And I know that all this will make the entire run from P to G long and potentially boring....

BUT we all know that, even when the course has been set well, there can subsequently be a consistent shift in the wind that favours one route against the 3 other possibilities. AND shifty winds may mean that one particular route is favoured on some laps and another route on the other laps. AND there can be enough variation in tide in lighter conditions to favour just one route.

AND we all know that ROs, even at Nationals, have set these marks badly AND failed to reset them between races when it was so obviously necessary, or have failed to reset when there has been a windshift.

If you get the impression I don't like the inverted P course, then you'd be wrong! Like Bob, when the Inverted P course is properly set AND when wind and tide variability is present but limited, I too like the opportunity it gives helms to show skill/judgement in their choices of route, evidenced by their gaining distance/places over less skilled helms (and when we are honest sometimes due to good luck!). Even if the wind remains steady in direction then it gives boats an opportunity to seek clearer rounding of the marks, clearer runs and cleaner beats to SF to gain over other boats. If helms don't like it because they have difficulty working out which route to take, then the sooner they do work it out for themselves the better for them - because they're then likely to make better decisions in the entirely similar decisions needed on less crowded parts of courses, eg on where to beat from SF to windward mark (left, right or centre), and where and when to gybe on downwind legs of square or trapezoid courses! And so improve their results generally!

So, I suggest :

1 we should not sail the inverted P course with a leeward gate when the wind is likely to veer or back during the racing, be very shifty, or when the variation in the strength of tide in this area will affect helms's decisions significantly;
2 it's worth considering using just the one leeward mark when restricted racing area means the inverted P offers a larger better course than a square or a trapezoid could, and when the wind is strong;
3 the relevant Sprint 15 Committee members must brief ROs about when to adopt and when to avoid the inverted P course, and how to set the P mark, SF line and leeward gate marks (or a single leeward mark); must remind ROs to note whether boats were reasonably split in both their choices of route in a race, to ascertain the need for the marks to be reset between races (better if all this is done in advance in writing, giving reasons for the relative positioning - I occasionally act as RO for Class Open Meetings, and am quite accustomed and glad to work from specific instructions on course requirements from Class Associations).
4 we should have a briefing that reminds us of the rules to take into account when approaching and rounding the wing mark, when approaching and rounding the P mark, when approaching SF downwind, when crossing beating boats, when approaching and rounding at G, and when crossing downwind boats on the beat from G to SF. We shouldn't need these reminders, but.......

If the above means we don't often sail the inverted P course, then so be it. In unsuitable conditions I'd prefer to sail a Trapezoid that involved almost exactly the same lengths and angles of legs as can be set on an inverted P, but with the 4th (run leg) and the 3rd (2nd reach leg) of the Inverted P taken as 3rd and 4th legs on the Trapezoid, with the other 2 legs being unchanged.

Bob's "d" course enables the relative lengths and angles of the legs to be kept, by changing the order of the legs from those of the inverted P or the Trapezoid. But compared with the Trapezoid it introduces more opportunity for encounters in the sailing area between the SF line and the windward mark, especially between leading reaching boats being forced to keep clear of leeward slower boats on a beat - the leaders have the skill to avoid collision but may lose critical distance/places to close rival(s) who don't have to deviate their course. But it may offer a better course than could otherwise be used in restricted waters. It would help if a spreader mark was introduced at the windward mark to keep upwind and downwind boats apart in that vicinity, but the likelihood of crossing boats in a wide area around and "left" of the "d" mark would remain.

Finally, while I really don't like small "starboard hand" courses because of the potential problems at the windward mark in large fleets, sometimes in some restricted waters there must surely be a case for "P" and "b" courses for smaller fleet events - eg some of our Travellers?

Not sorry about the length,

Hi,

I forgot to say that there also needs to be a suficiently long gap from the P mark to the Start Finish line, so that downwind boats have plenty of room to avoid boats beating up through the Start Finish line. This has rarely, if ever, been a problem because ROs have generally left a sufficiently if not over large gap between P and SF. Further, beating boats tend to tack for the SF line to pass close to the committee boat or the pin (so that an adverse windshift won't force an extra tack or 2?) and so will cross downwind boats quite a long way from the SF line.

I don't have a suggestion for how long the distance from P to SF should be.

I don't recall there ever being collisions between crossing boats in this area and the critics of the Inverted P course don't seem to mention this area as creating problems - but if someone knows better I think we should hear about it!

As regards the vote, I voted "yes", but I really wanted to vote "yes, but not when ROs set poor courses!" I have to agree that those who have only attended the Nationals in recent year will have had particularly poor experience due to poorly set courses. Which is why I want the Sprint Association Committee to provide ROs with explicit requirements to make future racing more enjoyable for the whole fleet - the bulk of which has to cope with the brunt of the "close encounter" situations, sometimes in quite large numbers of boats, that the fleet leaders rarely if ever experience.

Seems to me that there is little difference between a badly set inverse P course with a gate and one that had no gate in the first place. The gate is a nice feature if is set well - but we do not want to use the course in high winds or cramped spaces so that we do not make collisions more likely.

I would like to thank everyone for their very helpful replies. Whilst I have attended Sprint events that use the inverted 'P' course, I usually follow the boats in front of me, which is most of them. However, as regards the laying of the course, I have further questions.

1) Is it true the leward gate, the starting line, the 2nd P mark, and the windward mark, are all placed directly in a straight line with each other?

2) Do sailors ever confuse the 2nd 'P' mark for the windward mark?

3) Should the 1st 'P' mark be placed precisely at right angles to the windward mark? And how tight should our reach be to the 2nd 'P' mark?

With thanks,

Andrew.