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Past Publications

Following is an assortment of pieces published at various times and in various media.
Some appeared in print publications, others on and others still on other sites. 
Dario Valenza has contributed magazines including Seahorse and Australian Sailing, has starred as a commentator and expert on television and has delivered university lectures. 
The writings below are reproduced where copyright allows and in no particular order. 
They are carried over from previous versions of our websites and are featured for you to browse out of interest. For brevity illustrations and formatting are not reproduced and some may be abridged. 
Note the dates. Many ideas may have changed since publication because we are always learning!
If you wish to use any of these texts for any purpose please contact us.

In October 2001 We ran an educational programme involving a group of 'boat-crazy' high school age students. Here are some of the answers to questions arising from the programme. For instance we explain what is meant by ‘prismatic coefficient’ and how this vital characteristic of a hull affects its motion through the water.

Here is the reply that turned out to be the first in a series of quite detailed explanations of design terminology. For those of you familiar with the matters discussed, it is only fair to warn you that these articles assume no prior knowledge and are therefore qualitative and perhaps oversimplified at times to get across the essence of a concept.

Cp: In short, it is a measure of the fullness of the ends of the underwater body. As you probably know, a prism is a shape with a constant cross-section in one direction. For example, a cylinder is a prism with a circular cross-section that remains constant along its central axis. 
Anyway, imagine a prism whose cross section is the biggest (largest area) section of the underwater body. In other words, project the biggest canoe body section forward and aft to the waterline ends. The volume of this shape will be: 
Area of Midsection (AM) x Length Waterline (LWL).
Now, if you sit the boat inside this shape (no foils), it will touch it at the midsection and at the ends only, leaving some empty volume at each end around and below the hull where it tapers. 
The prismatic coefficient is the 'relationship' (ratio) between the volume of this imaginary shape and the actual volume taken up by the hull. 
Working out hull volume by hand is tedious but not hard (use Simpson’s rule to work out the area of each section then relate the area of each section to the length and get a volume. Remember the units: metres x m x m = m^3). 
Hull-modelling programs can do it in a second. 
If you already know the boats displacement (weight), you divide it by the density of water to get the volume.

When you have the two volumes, you divide the smaller one (always the actual hull volume) by the bigger one (the imaginary prism) to get a decimal. 
For yachts the prismatic is usually between 0.420 and 0.620. A prismatic of 0.430 is very low, meaning that the hull volume is less than half the volume given by multiplying the midsection of that hull by its LWL. A prismatic of almost 1 would describe a barge with virtually constant cross-sections, or a ship with a bow-bulb. 

So Pc = (Hull Volume) / (AM x LWL).

This ratio immediately gives us a feel for what kind of speed the boat is optimised for, and hence what kind of wind conditions it will like. 
Take a hull with a low Cp and one with a high Cp. If both hulls have the same displacement, the one with the low Cp will have skinny ends and a fat midsection, the one with a high Cp will have fat ends and a small midsection. This is because both must have the same hull volume but the volume is distributed differently.
As we move back along the boat from the bow, the sections get bigger. If they get bigger quickly and stay big to the stern, then the maximum section must be smaller than a hull where the sections get big gradually and pinch in again at the stern. 
The hull with the low Cp has finer (sharper) waterlines forward, a narrower transom and less wetted area than the one with the high Cp. It is closer to a half sphere. In light airs, wavemaking drag is a small component of the overall drag so most of the drag from the hull is due to wetted surface area. Reducing wetted surface (lowering the prismatic and making the sections closer to a semicircle) will give less drag in this situation.

A high Cp means a smaller midsection at the expense of more wetted area. As speed increases, wetted area drag goes up roughly proportionally with speed. Wavemaking drag goes up at a greater rate and typically starts increasing very steeply at hull speed (the speed of a wave the same length as the boat). At hull speed there is a big bow wave, a ‘hole’ (trough) in the middle and a wave just behind the transom. At this speed a high Cp and hence a smaller midsection means you are punching a smaller hole through the water. Fatter ends also give buoyancy and stability when the wavetrain gets longer and the hull is supported on two crests at the two ends. 
From our earlier discussions you will remember that water always exerts a ‘normal’ pressure force, meaning a force perpendicular to the surface it is flowing past. This force is smaller at lower water pressures, but is always there as long as the flow is attached. This normal force has an aft component wherever the hull gets larger as you move aft. It conversely has a forward component wherever the hull sections get smaller when moving aft. It is desirable to allow ‘pressure recovery’ in the back half of the boat, however, the tendency of flow to separate (keep going straight instead of following the hull) limits the amount of curve we can put in the back half of the boat. This consideration becomes more important with faster water flow and more pronounced wavetrains, another reason why high prismatics are better adapted to higher speeds.

...One need not do all the math to make a judgement about a boat. A qualitative feel for ‘prismatic’ is valuable in assessing hull shape. It is also worth noting that a similar argument on volume distribution can be made for keel bulbs: a long bulb with full ends is more suited to strong winds whilst a short fat one with tapered ends offers proportionally less drag in light airs. Once again though, we must remember that this is only one of many considerations. 
For RC yachts and multihulls where longitudinal stability is important on off wind legs, ‘prismatic’ (one can also consider the forward and aft prismatic separately) is vital in determining how much sail the boat can carry in power conditions…

Recommended texts: 
"The Symmetry of Sailing" by Ross Garrett. "Principles of Yacht Design" by Lars Larrson + Rolf Eliasson. " Recommended websites: (for ships), (for kayaks),

November 2001: The next question was a bit more vague, enquiring about the merits of overhangs to the waterline:

Ms are only measured overall, so they tend to have plumb ends to keep max waterline at all times. Interestingly, some Ms optimised for light airs do have a bit of overhang. This reduces wetted surface area and reduces Cp. 
Ten Raters trade off waterline length against sail area (an M, for example, even with plumb ends, makes quite a short 10, so it is entitled to massive sail area). If an M can handle the giant ‘10’ rig it is entitled to in any perceptible breeze, it has too much volume in the hull and is probably overbuilt. A heavier bulb helps, mainly upwind, but generally dual Ms get results because they are top-notch designs, because the wind is light and because they are well sailed.

So why the overhang? Well, length is ALWAYS good. Displacement sailing is all about length. When a 10 heels, it is designed to sink slightly into the water. There is a bit less volume designed into the topsides in the middle than there would be if the ends were plumb, so the hull sits into its full heeled waterlines, stem to transom. There is a bow wave and a stern wave, so the water level at the ends is higher than in the middle. Downwind, as the boat goes faster and the wave train gets longer and bigger, the middle of the boat is sailing in a hole and the ends are in wave peaks, so the faster you go, the longer the boat gets. This is very convenient because in the light stuff the boat is shorter and has less wetted area, but it gets length when it needs it most. You want waterline length to get the bow and stern waves as far apart as possible because water wave speed is related to wavelength and because a boat cannot 'overtake' its own wake unless it is planing.

Overhangs are good in waves because they can dampen pitching (great example of this was the ‘92 match between the red Kiwi boat and Il Moro in the Louis Vuitton Cup). 
They also make the boat handle better downwind, but this is more a function of the longer waterline than of the buoyancy they provide. 
Lastly, think about the heeled situation. If you play it right, by making the middle of the heeled underbody smaller and the ends longer and more buoyant, you are increasing the heeled prismatic, which is good when its windy and you're pressed and going fast...

1999: Comments on our IMOCA 60 reproduced by various print outlets:

Liberty was designed at a time when the Open Class typeform was coming under review. Extreme beam, high aft prismatic, flat decks and forward raked relatively heavy wing masts were features of highly specialised reaching machines with increasingly dubious safety characteristics.
We decided that a more all-round approach was needed. Experimentation in the class have already shown what 'corner' of the design space is advantageous. Now it is time for refinement.
Initial (hull form) stability is in important consideration because of the 10 degree ballasted static heel limitation. Taking the beam right aft makes for a hull that likes high speeds and sails on an off-axis waterline when heeled. With a canting keel, offset/asymmetrical dagger boards and careful optimising of centres, this approach will yield a fast but tweaky and trim-sensitive boat with many critical variables needing adjustment under sail.
Such a hull will inevitably be sailed at optimum only a fraction of the time, placing additional stress on the shorthanded crew.
We opted for a more tapered hull shape with relatively large fore/aft symmetry, a moderate prismatic and narrow waterline. The sections are extremely flared, with max beam on the class average-to-high band, but only at deck level.

Inverted stability and safety solutions are addressed in the boats very lines. A cambered foredeck, a large volume coachroof and less beam in the ends, tied together with a subtle sheer line, all contribute to a ‘lower’ inverted centre of buoyancy. Special care was taken in the design of the coachroof to prevent water ingress when inverted and/or damaged. The basic dimensions of the boat show some reluctance to sacrifice light air and upwind performance for more extreme top speeds.

Uniquely, some structural components and hull panels made for a third generation Farr Whitbread (now Volvo) 60’ were adapted and incorporated into Liberty's construction. The opportunity to use some bulkheads and topside laminate presented itself after our hull concept had been thoroughly explored. This meant a substantial cost saving and was decided upon only provided that we could work it into our original shape. As it turned out, the Kevlar-epoxy panels were great, eventually making up the bulk of the hull's primary shell. The toughness of Kevlar was a welcome bonus, with carbon still present in areas where it is of greatest benefit.

The potential of this boat is awesome. The options available in this class are bewildering. We followed the keel and rig configuration debates whilst doing our own research and considering the choices... Interestingly, the project started out taking a canting keel virtually for granted, but it was ultimately discarded in favour of water ballast.
Both sides of the debate concede that any advantage either way is marginal and limited to specific conditions and points of sail. Specifically, the 10 degree ballasted heel limit in the class penalises a swing keel more than it does water ballast.
With the more slender underbody, the trade-off means less form stability, so ballast stability (in whatever form) has to increase marginally. Given the lack of local experience with carbon keels and the marginal difference between the options, we went for a fabricated steel 'box' keel spar with a composite foil fairing. This brought the keel/bulb package to 3400Kg. Plus 3000Kg of lateral water ballast per side and a trimming tank in the forepeak.

The D section carbon mast was engineered by Murray-Burns-Dovell. The deck-stepped configuration with three sets of full width swept back spreaders is simple and light. Liberty carries significant rake and moderate pre-bend. To allow the possibility of flying fractional kites, there is no fixed masthead forestay. Instead, the hounds and spreaders are slightly higher up the mast. A provision was made for deck compression struts but they were later discarded in favour of a removable Vectran babystay off the lower spreaders.
The allowable 6’ of overhang is distributed between a 4’ bowsprit and 2’ of boom overhang. The ‘centres’ are a fair way aft, the rig being stepped at 50% LOA.

Simplicity and structural rationality have allowed us a similar power to carry sail on a platform with a higher ballast ratio, lower wetted surface area and similar displacement to the current trend. Liberty was amongst the first of the crop of modern ‘sensible’ Open 60’s, a boat conceived with average speeds, rather than top end bursts, in mind.

Extract from interview in 2000: Carbonicboats was responsible up to delivery and took on successfully the job of sourcing and signing up the title sponsor. One year on and the boat is being prepared for the Around Alone by her skipper John Biddlecombe. The boat is entered and we wish him the best of luck in his globetrotting race! Living in Sydney and being set up for singlehanded operation, the boat has had little chance to race. 
Rather, she has been piling on the sea miles singlehanded. 'Biddles' is confident that he is learning all along about what makes Liberty tick. Recently the boat was third over the line in a record 90+ fleet for the Stratfield Pittwater (Sydney) to Coffs Harbour race. She beat some specialist offshore sprinters and was only 'pipped at the post' by considerably longer fully crewed racing machines.

November 2001: Reproduced below is a letter sent to members of the yachting community by the enthusiastic promoters of BRONCO, a Box Rule for rating Ocean Racers. Everyone was given the opportunity to have a say in what seems a genuinely refreshing initiative that will hopefully spark constructive debate. Having sailed with Rob Drury and been asked personally for a contribution, I was more than happy to speak up. looking back and reading this correspondence in 2010, the similarities to the now very popular Class40 Rule are heartening.

The original text from Rob: “…I come from my own initiative, unbiased, and without any authority or agenda other than to widen the interest in and the wish to advance offshore yacht racing. And the means for this to happen needs to be available-thus the web site This site has been created to facilitate BRONCO. Yacht clubs and/or event organisers offering BRONCO races will need a certificate to accept entries.
Sections of the sport of offshore yacht racing seem in decline. The absence of a suitable system not based on handicaps for good hard challenging competitive offshore racing may be the reason. A box rule seems an answer. 
Yacht design and construction has seen substantial advances but in general, the framework under which yachts' race has not. Your input to the foundation of a new class is invited as are any comments you may have.
Everyone wins with BRONCO: designers, sailmakers, builders, industry suppliers, yacht clubs, yachtsmen and yacht owners who want good open competition outside handicap/rating and One Design type systems.
I look forward to your involvement.
Yours sincerely,
Rob Drury,
Sydney, Australia
1st November 2001”

Carbonicboats reply: Following are some thoughts on how the rule might treat specific aspects of design. Open feedback and discussion of these points should help form an idea of what owners and sailors want. 
BRONCO needs to appeal to the broadest possible cross-section of prospective and existing owners in order to summon up sufficient entrants, but it has to distinguish itself from the alternatives that have left some disenchanted. The intent is clear enough: to produce fast, fun, safe oceangoing yachts that will be scored in the order they cross the line. Development should be encouraged to keep the boats interesting but without allowing them to become too extreme or prohibitively expensive. 
Provisions should be made to allow high profile open class boats into the fleet. Their presence would be beneficial both in terms of numbers and publicity. BRONCO boats should be competitive with such esoteric visitors and have the strength of being less specialised. 
So the first thing designers need to be told is exactly what typeform the rule should favour. This should coincide with what kind of boat people want to build. These ramblings intend to air my personal view and hopefully propose a model as an initial option.

Divisions: Each boat will compete with others of equal overall length. 30’, 40’, 50’ and 60’ are common maximum lengths. Perhaps an existing conservative 33’ yacht (one built prior to the rules official launch) might reasonably be allowed to compete in the under 30’ division. Maybe the 50’ and 60’ nominal lengths should refer to waterline length and stipulate a maximum 3’ and 4’ overhang respectively so that, say, an Open50 will be 3’ shorter than a BRONCO50. Any such clauses however detract from the simplicity of the box rule and should be carefully considered.

The boats should meet ISAF and AYF special regulations for cat1 or cat0. This should take care of equipment carried, stability (more on that later), hatches etc., but cannot be an effective engineering guideline. Structural rules are always a thorny issue. Specifying minimum panel weights and minimum reinforcement arrangements should be avoided because the rule minimum will invariably be taken as a ‘safe’ value and may not be adequate for boats with unconventional arrangements (unless the minimum is conservative which would add material unnecessarily thereby increasing weight and cost) . Maximum unsupported panel areas, minimum core density etc. have actually proven counterproductive in the past. At the risk of inciting cries of ‘arbitrary!’ the rule should simply require certain outcomes that would be up to the designer to demonstrate. Safety factors in the form of lateral acceleration and grounding speed for the fin would be relevant examples.

Sails: The design and content of the sail wardrobe should be unrestricted, with limitations on the number of sails carried in one race AND a maximum number of sails that may be measured each season. Maybe an allowance for a certain number of additional old sails (with strict limitations on what constitutes an old sail) would encourage people to trade/keep using sails. For every race there shall be one mainsail, one tri-sail and one storm jib, the rest of the wardrobe may be any combination of beating headsails, code-zeroes, kites, whatever…

Spars: One mast, conventional mainsail boom (as in swivelling behind the mast as opposed to Aero Rig or wishbone) with unrestricted gooseneck height, only one carbon conventional spinnaker pole allowed (any other can be alloy), only one bowsprit.

Should there be a provision for rotating masts? Here are some pros and cons: There is no proven overall performance advantage to a wing mast on a monohull. They are heavier than a conventional spar made of the same material so they have to be shorter (unless a stability penalty is accepted). Displacement/stability, pitching and sailplan aspect ratio all suffer. They are a handful in severe weather. They are arguably more expensive. However, they represent a technology in its infancy and have already been developed significantly. In Australia there is very little experience with the technology and the marine industry would benefit from playing with it, especially in terms of opening the doors to overseas orders. If a wingmasted Open Class should turn up and happen to get reaching conditions (an angle where a wingmast has an edge) they would be unbeatable, but, after all, reaching is what Open boats do best.

I think that a good compromise would be to allow that kind of tinkering on the smaller boats where rectifying an error would be less costly, the engineering less extreme and conversion more expedient. 
Should the above justification apply to materials too? Well, absolute cost is probably irrelevant to the individual owner who is simply concerned with relative cost, but it must be said that you can get away with a filament wound carbon mast on a 30 footer, so the leap from alloy to carbon is relatively smaller on little boats (as well as being steadily decreasing).
Banning carbon spars in a new class, especially in the smaller divisions, could put off more owners than it might accommodate. In my opinion rigs are one area where carbon is definitely worth the expense.
Canting rigs are banned even in the Open classes. There really is not the interest to economically develop them in any new class (unless of course we want our 30’ division to be allowed to play with them)...

... Philosophically: The basic choice to make is weather to premise the rule with “anything not specifically prohibited shall be allowed” or “anything not specifically allowed shall be prohibited”. The first option appeals to me as the more attractive for development and simplicity. Administration of the rule in its initial stages should be fairly flexible with discretion allowed for interpretation of unforeseen quirks and how they may relate to the spirit of the rule, keeping in mind the interests of existing owners.

A minimum displacement may be a good idea to keep the boats sane. A minimum hull weight also seems necessary but it must be made clear that it is to go into structure and accommodation, not bilge lead. Perhaps separate minimum weights for the hull shell and ‘the rest’. Specify a set number of watertight bulkheads, frames, stringers (water ballast tanks count as stringers) etc, thus leaving furniture as the only option for the remainder of the weight.
Construction materials should be limited to glass, timber and foam for the 30’ and 40’ and more liberal for the larger boats where the scale of the project makes materials juggling a more flexible exercise. Definitely no Nomex and no high-temperature baking. Keel fins should be steel. Rudders unrestricted but with generous safety factors for the shafts (here innovation in the way of replacement systems, collision management etc. should be encouraged).
Specific limited areas where exotics bring real advantages should be looked at. I suggest that in way of the keel frame, chainplates (indeed the chainplates themselves) and rudder bearings carbon is a good idea. In the forepeak a Kevlar outer skin is also a good safety feature.
In these considerations it is worth considering that each division should have slightly different biases. The smaller boats should be more open than the larger. 

Sail area would be best controlled by defining a rectangle delimiting the sail plan. The Open Classes use a fixed maximum length of overhang that may be split between bowsprit and boom end. Restricting mainsail luff only may lead to artificially raised booms. A mast height above the water is necessary and would have to be in conjunction with a minimum height for the mast heel to encourage decent sized coach roofs.

Interior volume and accommodation is once again very difficult to define reliably. Any specific figure will promptly be adopted as the standard and possibly not be sufficient for boats with unusual layouts. Perhaps a definition of the tasks that need standing headroom to be performed should be included in the rules, allowing the designer some latitude on how to satisfy the requirements.

Finally to the issue of stability: There should be a choice between water ballast and a canting keel. Canting keel yachts should be allowed a fixed volume of central water ballast distributed in any way required for trim.
Lateral water ballast should be traded for beam. A narrow boat should be allowed more water than a wide one. This little clause should discourage the trend for ultra-wide boats with huge initial stability and light keels. Also, existing boats with moderate beam will not be outclassed by beamy lightweight designs. An ultra narrow boat half full of water would have limited interior volume, so a nice compromise will be encouraged.
Again I would recommend to treat each size appropriately: a canting keel on a 30’ is much less threatening than on a 60’. 
Regarding canting keels generally, some sort of tradeoff between the lateral displacement of the bulb and overall beam should be considered. The fin should only be allowed one degree of freedom only. The remainder of the foil geometry should be unrestricted, thus encouraging mucking about with daggerboards, different rudder combinations etc.
A vanishing positive stability angle in most unfavourable trim should be specified together with a maximum area ratio between positive and negative stability curves.

I hope the matters raised will encourage discussion. Specific numbers for parameters within the rule will follow a consensus on what the outcome of the rule should be and how it is to be encouraged. Ocean racing needs this rule and now is the time to have our say.

Following is the last SRCYC Newsletter for 2001:

Saturday 1st September 2001 was our first club meeting at D.R.C. We plunged straight into handicap championship scoring, the previous scheduled social day having been literally blown away by a monster westerly.

The weather was unsettled, the tail end of a southerly blowing itself out and bringing occasional showers. What looked like the first afternoon northeaster of the season gradually snuck in to replace it. This all resulted in very fluky conditions. Each cloud front brought a burst of breeze from a seemingly unrelated direction. There were random glassy patches and local inversions of direction thrown in. We set a fairly conservative course and did a couple of scratch races to acquaint ourselves with the new waters. The holes in the breeze made it A rig weather, but the gusts tested the light rig to the extreme.

The first race was fought at the front end between Phillip Page with his Berloiz, Robert Page also with a Berloiz and myself sailing Ajax1 with a brand new fin.
In the unpredictable puffs the handicaps all but evaporated by the first top mark as the scratch boat would sit just beyond the line only to start moving in the same gust as the later starters (‘Familiar story’, some will think). Robert was plagued by radio trouble and spent the rest of the day kindly observing and scoring.
Maurice Fletcher arrived with his new Frank Russel boat in time to start Race2. He proceeded to win that race by miles, followed by Ajax1 engaged in a hard-fought struggle with Phillip, never more than a boatlength apart and overlapped at the finish. Race3 was a true test of light air sailing skill. Phillip demonstrated his uncanny ability to keep a boat moving when others just drift to a standstill. Maurice managed to edge along behind Phillip, close enough to be a threat. Ajax1 was out the proverbial back door at the first shift, finishing mid-fleet.

We agreed to run the minimum of four scoring handicap races, followed by some ‘social’ scratch sailing.
The last race was breathtakingly dramatic, a short sharp squall of heavy rain sweeping the course shortly after the start. It brought downdraft more than actual breeze. Gray filtered light and water boiling with raindrops framed the boats spectacularly. Here we discovered another perk of the venue: the clubhouse offers considerable shelter from the rain in full view of the racecourse...
As it happened, Ajax1 picked up the downdraft first, wound up to the mark well heeled and took off on the reach whilst Phillip and Maurice had to tack for the mark. By the last short beat to the finish the sun was out again and the breeze had died, the boats bunched up again, but the finishing order was the same as at the first mark: Dario, Phillip, Maurice.

Now it is only a matter of time for our fleet numbers to grow again. We have a regular venue thanks to the efforts of Robert and Phillip Page in negotiating with D.R.C.
I would like to take the opportunity to appeal to our membership on two levels. Firstly we must get out there and practice our beloved sport. We need to be seen to have a credible number of committed competitors. Secondly, and needless to say, we should make an effort to charm our hosts at D.R.C. proving ourselves to be clean, polite, helpful, reliable and competent. Just get out there and have some fun!

Race Reports:

SRCYC 2001/2002 Pointscore Round1 
Podium Results: D.Valenza: 1,2,3,1. P.Page: 2,3,1,2. M.Fletcher: 4,1,2,3.

The first round of our scratch championship took place on Saturday 15th September under a glorious Sydney spring sky. The first few races were sailed in a consistent westerly, which proceeded to die off giving way to an early season northeaster. We initially set the course well into the bay to the right of the clubhouse. There, a trough in the hill profile allows the breeze to reach the water quite cleanly. The course was intentionally long, allowing us to learn about the breeze on that entire quadrant of the sailing water.

Race 1 saw an orderly, clean but tight start with the entire pack crossing tacks right up the beat. Phillip Page’s Berloiz and Ajax1 snuck around the top mark on a slight shift and scooted off on the reach with a bit of a lead. Maurice Fletcher was next around with Tim Harrold and Robert Page hot on his heels.
Bruce Hilliard joined us with his Archer design in time to start race3. Throughout the day, the fight for third across the line was the most hotly contested. The clearest indication of the kind of racing being had is that everyone managed a podium finish at some point in the day.

With ten races sailed, the emphasis was on consistency. Races 3 through 6 took place in very light and variable conditions, typical of this time of year when the sea breeze struggles to fill in. 
Once again Phillip managed to edge ahead through sheer experience and concentration, accumulating a disproportionate number of wins.
Ajax1 had the largest number of second place finishes but a single fifth place was enough to hand a very consistent Maurice Fletcher second on points.
The great improver of the day was Tim who managed a second and two thirds with rigs that still need sorting out. Robert and Bruce were always close enough to pile the pressure on.

For the last three races we experimented with bodily moving the course out and to the left into the new breeze. Every course change is another lesson learned in the characteristics of our new home waters.

Marblehead racing in Sydney is back! The fleet for this round of club racing was of a very high standard. There seemed to be no ‘stragglers’ and the field consisted entirely of carbon boats.
This is after all the Grand Prix class of our sport. The boats are fast, tweaky, technical and diverse, yet the simple restrictions on length and sail area keep racing very close. Australian designers were represented by Maurice’s immaculate semi-custom Frank Russel boat and two Dario Valenza Ajax1 specimens.

SRCYC 2001/2002 Championship Round1 Results:
P.Page,11. M.Fletcher, 22. D.Valenza, 26 T.Harrold, 36. R.Page, 39. B.Hilliard, 51.

A demonstration sail on the tidal waters of Homebush Bay completed a great weekend of RC boating. All classes were out for a full day of friendly sailing under the curious eye of prospective residents and the strolling public. 
Orchestrating the launch of a new apartment resort, the hosts kindly organized parking, a generous hot meal, drinks (definitely appreciated by some. You know who you are) and even sunscreen.
Robert Page, Phillip Page and myself represented the SRCYC with IOM sailors Daniel Weizman and Brad Gibson putting up some competition with their new Marbleheads. 
Daniel has made a textbook transition to the class, doing a number on ‘Factor’, a Derrick design originally built by Brian Dill. It is rumoured that soon he will be at the helm of a Paradox straight from the UK.

The racing was predominantly in very light airs and glassy water (as expected at this time of year) on a course without the slightest pretension of having a true beat/run. A relaxed day was had, with some skippers taking time out to enjoy the food, drinks (once again, you know who you are) and the carnival atmosphere.
On the racetrack, skippers could swap boats and play around with settings.

The event was a success in bringing our sport, in all its forms, to the public. The racing was enjoyable in the picturesque bay that featured the beautiful overgrown wreck of (presumably) a steel ’90 miler’.
Well, that about wraps up events for this month. I hope to see all of you at D.R.C. for our next meetings…

Race Day Report/Diary. Date: 31/03/2001 Conditions: light N, NE breeze building from glassy before noon to 8-10Kn and puffy. Sunny. Course: triangle, sausage, anticlockwise. Beat is to the right from the bank. Course bias: right side favoured. 
Field (top three boats): Robert Hales (Paradox); Dinah Hales (Skalpel); Robert Page (Berloiz). Comments: fleet of seven, quite strong but with only three internationally proven boats.

Race1: Ajax Mk1's first race. Go to launch and (how embarrassing) the rudder servo emits an agonized spasm and dies. New servo so seems a manufacturing defect. Deck patch off, spare servo out of spares box, pop it in, plug it in… Lesson learned: new access and servo mount are good. Ok, so race one will be my discard. Take the chance to sail around a bit, avidly observing the feel of the new boat. With the light air sail settings (leeches very open) the helm is quite neutral. Rudder Mk one is quite big (145 cm2), we will gradually chop bits off and observe the effects on trim, balance, height and wave making. Experimenting with timed runs to the line the new boat seems much more forgiving: Turning saps less energy.

Race2: Milled around close to the line, sat near the favoured end staking a spot. Squeezed in on the gun shooting between Robert Page and the pin with about an inch to spare. No contact so tighten up, get some separation and foot into the lead. Played conservatively after that, stretched ahead in clean air. Position: 1st

Race3: Thirty seconds to go and I sail into a bit of semi-submerged rubbish… luff up, ease off and back out of it. As soon as the boat is free it's a mad dash to the line. The closest end happens to be the windward end. 3 seconds and the pack seems to be on the edge of being early…they ease off to kill time and open up a gap. I jump through it about 3 seconds late but with pace. Like last race, sheets on, and wind up. Bit more pressure this time and leech is still open, so not as tight as Id like to be, but enough to squeeze ahead, pick the tack and stretch in clean air. Position: 1st

Race4: Breeze might be filling in but I keep the same sail settings. Rig dead straight, tops quite open. This time there is no gap for me at the top end. Put the breaks on and duck under Robert Hales, Robert Page and Dinah. Accelerate under her quarter and foot away for pace, foot so hard that I end up almost directly in front of the first boat in the second pack. Course now heavily biased to the right. There is only a short port tack dig. All marks are to port so I'm locked out…went too fast to be able to tack and duck, could possibly be clear ahead of Dinah, but the two Roberts would constitute a wall of starboard tackers. Of course they carry on right to the lay. So it's a fourth around the first top mark. Dig down low on the first half of the reach and use the first law of marine gravity: what goes up must come down. Squeeze up under the Skalpel, just breaking the overlap before four boat lengths and rounding third. Meanwhile the two Roberts have stretched out considerably so all I can do on the second reach is close the gap. Interestingly they tack away immediately at the bottom mark, onto the lifting starboard tack. Being fairly close by now and not wanting to follow in their wake, gamble and carry the port tack into the bank. Tack on a fresh puff off the land. Dinah also took a dig on port, but not quite to the corner. Now she is some 5m abeam of me. Two leaders tacked across about ¾ of the way up the beat. Paradox cleared Dinah and lee-bowed me gaining the inside track to the mark. The Berloiz had to duck the Skalpel and tacked behind me. Now we had a race. Down the run we both went very deep at first. Max ease on the sheets, yard over-square and boat rolled to windward, edging ahead of the heavier Paradox. Almost past the bottom mark I was again able to come up, break the overlap and round ahead. This time I tacked immediately and was just able to shoot the line. Position: 1st

Race5: jotting down notes fresh-minded between races gives little breathing room! With the NE breeze consistently above 8 knots now it was time to play with sail controls, tightening up the A rig. The notes for this race read: 'Last second spin to miss leeward end. Don't run the line! …Started late but clean. Tacked early, squeezing. Back on starboard and only two crossed. Couldn't squeeze them off, footed instead, tacked, cleared…” Commenting about the new boat at the finish: ‘I think Ill keep this one'. Position 1st

Race6: After the break for lunch swapped boats with Robert Page. Most orderly start of the day with Paradox, Ajax, Skalpel and Berloiz in that order from windward to leeward all on the line and all with speed. It is always instructive to sail someone else's boat. The differences in feel were very interesting. Powered off to leeward whilst Robert Page used Ajax's height to squeeze Robert Hales up. Tacked onto port convinced that I would clear Dinah but had to slam tack when I realized the misjudgement. Cost me a place. Pretty close stuff! Robert and Robert jostled for the lead, quite evenly matched until Ajax hit a mark, Robert unfamiliar with the boats turning circle.

Race7: Back to our usual craft, breeze building and course very biased to the right. What looked like a great start went horribly wrong when I darted through the line in a perfect windward position a split second too early. Around the end costs heaps. Now fighting through the second pack. Put in a few tacks trying to keep clean wind and using every puff. 6th at the top mark. 5th at the bottom mark. In the lead pack by the last top mark. 3d at the last bottom mark edged into second between the two Roberts by the finish. Position:2nd

Race8: Another mediocre start buried under Robert, Robert and Dinah made for an intense fight all around the course. Squeezed an overlap at the last possible minute (was that four boatlengths?) before the final bottom mark, gaining the lead from the Berlioz. Sailed toward what looked like more pressure instead of slamming on the mark. Robert, Robert and Dinah simply tacked inside me seeing that port tack was a dud call. Lesson (re) learned: Don't go out to the corners, especially not when in the lead! Position: 4th.

Date: 07/04/2001 Conditions: light N, clocking NW. Wind building from 5-8Kn before noon to 10-12Kn and gusty. Sunny. Course: triangle, sausage, anticlockwise. Beat is to the right from the bank (same as last week but with top mark closer to bank and bottom mark deeper into pond). Course bias: right side favored but very shifty. Gusts off the bank lifting on starboard, alternating to fill from opposite shore and lifting on port tack. Field (top boats): Robert Hales (Paradox); Dinah Hales (Skalpel). Comments: only three actually sailed, no points kept. Reason being that the bicentennial Park pond was blooming with vegetation and debris presumably due to heavy runoff from a very rainy week. Notes are sketchy because with murky water and all sizes and shapes of obstacles any performance data would have been random.
Club members voted to use Hinkler Park as a replacement venue for the foreseeable future. Observed boat sailing, experimented with sail settings, generally relaxing afternoon I guess...
Great shame that the pond has been allowed to deteriorate to this extent!

Date: 16/04/2001 Conditions: overcast, clouds coming through with quite sustained southerly wind at medium altitude. S, SE 5-8Kn dying out to a glassy calm by 1630. Drizzle bands bringing some pressure, but rain held off during racing. Course: triangle, sausage, anticlockwise. Beat to the right from the bank, sail up past helming position and away to top mark, reach to the left, reach around western peninsula. Course bias: good question! Utterly variable breeze influenced by wide lagoon, pond side reed, trees, currents and the whim of the Gods. Field (top three boats): Warwick Crossman (Struen Robinson modified Frank Russel Zero); Robert Hales (Paradox); Dinah Hales (Skalpel). Comments: fleet of six. Three internationally proven boats and a very strong Australian boat sailed by a talented helmsman. Warwick's boat is immaculately built by Struen Robinson in carbon/polyester. The hull has a moderate beam with very sweet, fair semicircular sections, even rocker, medium displacement and volumes just on the full side of mid-range. It uses a Bantock fin with a skinny bulb (circa10%), a IOM Skiff style 'pear planform' rudder and swing rigs based on Bantock carbon tubes. In the water the boat looks well balanced and doesn't make a fuss. I refer to it as a 'mature' design, firmly in the middle of the spectrum of ratios and proportions. 

The temporary venue (a saltwater lagoon) has a fairly peculiar geometry. Use clockwise or anti-clockwise course depending on breeze. The shoreline is dotted with reeds and some trees. 

Trying out a new rudder today. Smaller area, less volume, elliptical planform, 1/4 chord line straight. Henry Nehrybecki construction from Waliki's moulds. Carbon skins, hollow, carbon shaft. Max thickness 5mm. Area87cm2 (Mk1 was 145cm2). As expected weather helm increased slightly, just perceptible, especially in light airs. Wake looks the same but there seems to be more disturbance at the surface, possibly from greater thickness/chord ratio of elliptical planform at top. Today was part of our bi-monthly handicap racing series. Staggered starts and no time kept means that little objective data can be ascertained, but in the dying breeze the fleet tended to bunch together by the first mark, so racing was interesting. Having missed all but one of this season's handicap days my starting time was very generous initially.

Race1: Very confused light breeze. Started with Warwick, racing boat for boat. Split on short beat and came into top mark three lengths behind. Hung on for most of reach, lost a bit when he came up and hooked into a puff, but got some back when he had to come down again in the lee of the pines. Worked our way through the fleet by the lst mark. Coming out of the final mark it was Robert hales, Warwick and Myself. Tacked away to the right. Then tacked on a nock and got carried right to the line. Position: 1st

Race2: Started 5 seconds behind Warwick. Tussle to top mark, luffing match between Robert Hales and Warwick. Robert Page got through and I followed closely around. Dina Hales edged ahead on reach in clear breeze. Fleet compressed on reach, classic crowded wing-mark rounding. Fresh puff on second reach sorted us out, Ajax edged ahead perused viciously by Warwick, Robert Hales and Robert Page's now planing Berlioz. Overlap with Dinah doubtful so went outside at bottom mark. Robert, Robert and Warwick also playing it safe. Split immediately based on last race  but this time the lift came as I sailed out. Others spread fairly evenly. Was reluctant to hit the corner so tacked back and ploughed across the course on starboard. Everyone ducked. Tacked back and cleared everyone but Warwick, so ducked him and went to layline. Back on starboard and got that lift, had to crack off slightly into mark, the boat loved it. With the centres further forward, a bit more flare and a slightly wider stern coupled with more generous foils Ajax1 can foot better than Nexus. Maintained lead through run and last beat. Literally 6 boatlengths from the finish line the boat lurched to a halt, fell away and began to drift helplessly downwind away from the line. Upon retrieval by rescue boat it was discovered that a (very old) plastic shopping bag looped over the fin is not conducive to speed! Position: DNF

Continued: 07/04/2001 Race3: Well, last race's misadventure helped the handicap at least... notes read: ‘Good start, on time, on pin, passed Warwick by top mark by squeezing steady height. Very close first reach and fleet reeling us in. Lost him on 2nd reach and caught Robert Page. Walked away with lead only to pick up some more debris. Dinah also picked up gunk. Position: DNF. Comment: This run of pollution is very peculiar, mainly due to high water level and storm water run off from two weeks of rain. Generally this is a very clean place.

Race4: Slightly tighter sail settings, exits just horizontal when boat lying down on grass. Started a bit later than my handicap, squeezed in at top mark, ghosted clear in light air. Small rudder a help here. Almost dead calm by finish, scary being ahead in such variable conditions. Position: 1st

Race5: Ok start, a couple of seconds late. I have to work on my timed runs. In touch on first run. Gained lead by last beat and sailed off to the right. Coming back on starboard I gave it away by lee-bowing Robert Hales on layline to mark. Should have forced him to tack or duck. In ghosting conditions tacking under a heavier boat with momentum is suicide. He covered me to the starboard-tack layline to hold me out, meanwhile Robert Page snuck through to beat us both. Position: 3d.

Race6: Nailed the start this time. Handicap getting steep. Breeze died. Slowly catching fleet. When we were all sitting at the bottom mark, probably all in contact gunwale to gunwale and going nowhere we called it a day. 

Now to ponder the lessons... Will make some changes for next time. Tim Harrold (owner of second Ajax Mk1 hull) was sailing after a long wait for parts and a weekend sailing big boats. He only joined the races at a respectful distance in deference to those who are in the hunt for the pointscore. The two Ajax designs were initially identical in every detail, later varying rigs as part of our continuing experimentation. Tim is playing with very skinny section, thick walled tube.

Date: 04/05/2001 Conditions: light S, dying in the middle of race2 and creeping in from NE before snuffing it in the rain. Lightning storms looming, borderline conditions for racing. Course: triangle, sausage, clockwise (Anticlockwise from third race). Beat is to the right from the bank when course anticlockwise. Course bias: Not to sound repetitive, but with about 1 knot of breeze (from directly above) it was anyone's guess. Field (top boats): Warwick Crossman (Robinson re-worked Frank Russel Zero with Bantock fin and swing-rigs); Brian Dill (Own design); Phillip Page (Berloiz); Robert Hales (Paradox); Brad Gibson (Robinson re-worked Frank Russel Zero with Brad Gibson rigs). Comments: Last round of M GP series. Top NSW skippers present. 9 boats racing including 4 internationally proven boats. 
Not a good day for us... Amongst other things the experimental bilge lead we had been playing with proved a really bad idea in the drifting conditions (Tim and I were each carrying 400g of lead in the aft bilge to note its effects on pitching, turning and trim. The object of the exercise was working out how the change in moment of inertia influences behaviour). Once again, the testing program took priority over race results. Few races were contested and the finishing order seemed sometimes random. Phillip Page, Brian Dill, Robert Hales and Brad Gibson sailed very consistently for a very close resolution on points. The first Ajax came a disappointing 6th but at least we think we know why…

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