Star Class Honoring the Past, Leading the Future
Note: Warning, this article is quite a bit longer than I intended. I originally wrote this article five years ago but I never shared it. If you actually read it and find me in Miami, I will buy you a beer.
For years, our Class has avoided even minor tweaks to the weight limit to maintain consistency, stability, and properly determine its impact over time. As we approach the 20th anniversary of the implementation of the weight limit; maybe it is time to evaluate?
Has it had the impact we thought?
Is the formula equitable?
Is it easy to understand?
Could it be better?
Do we need a limit?
History
The weight limit was passed in 1997 and effective in 1998. It was the work and passion of Alexander Hagen of Germany. In fact, there were a variety of versions of the weight limit that developed until the final version was settled upon; the rule that we sail under today.
Several of our highest profile sailors wrote articles urging passage: Vince Brun wrote an open letter to the Class; Andrew Hurst of Great Britain, a Class member and publisher of Seahorse magazine wrote an editorial in Seahorse; Bill Buchan worked directly with Alex Hagen; and, Paul Cayard wrote a column on the matter as well.
When it passed, the limit was controversial and it was tweaked to help ensure passage.
“… (The formula)… provides a small righting moment advantage to the large helmsman which could prove important in gathering a two-thirds majority.” Mark Reynolds, “A Fresh Look at the Star Class Weight Issue”, 1994
By large measure, the rule has improved and benefited the members of our Class. We remained an Olympic Class status for 14 more years, our membership is quite a bit healthier, and the competition between teams has never been more level.
Currently, our formula allows a broad range of total sailing weight based upon the skipper’s weight. On the extremes, a 280 lbs./127 kg skipper can race with a 180 lbs./81.6 kg crew for a total weight of 460 lbs./208.6 kg and on the other end of the spectrum a small skipper at 160 lbs./72.6 kg can race with a 260 lbs./118 kg crew for a total weight of 420 lbs./190.5 kg For practical purposes, most teams race within this 40 lbs./18.1kg range. But, how did we arrive at our current… range and ratio?
The Nelson Marek Study
Twenty-six years ago, two major studies were produced prior to our weight limit being passed. I am not sure how many people reviewed these studies but they are available for anyone that is interested. The Nelson Marek study and the subsequent Aerohydro study. Aerohydro utilized the righting moment results of the Nelson Marek study to support their findings.
On February 21, 1994, Nelson Marek was commissioned to study the best ratio to use to account for the effective hiking positions of the skipper and crew based upon a variety of weights. Per their overview statement:
“[a]n analysis of the effects of fully-hiked crewmembers and partially-hiked helmsmen on the stability of International Star Class racing yacht was (sic) performed to accurately establish their relative contributions to stability and performance. A combined crew weight limit formula designed to provide similar performance potential over a wide range of helmsman/crew weight combinations is suggested. This formula is based upon equal stability production at a sailing heel angle of 15 degrees with a crew leverage factor of 3.8 and a helmsman leverage factor of 3.2.”
As you have probably noticed, this analysis really only accounts for the weight position and hiking positions while sailing upwind. However, as most Star sailors will note, this is the impetus for conjuring a weight limit in the first place. No one has ever suggested that we need to have a limit on small sailing teams because they have been going too fast downwind. Nevertheless, the subsequent Aerohyrdo study does account for boat speed, up and downwind, and thereby helps address some of these unanswered questions.
Nelson Marek came up with a fairly reliable formula to account for these differences in the size of helmsman and crew; 3.2 compared to 3.8 respectively. To simplify, Nelson Marek determined that there is only about a 15% difference in effectiveness if more weight is shifted to the crew who is lounging in his hiking vest.
Nelson Marek therefore, determined that the ratio issues were not significant but devised a proposed ratio anyway. However, they did emphasize that total weight was a significant factor:
“The resultant increase in total combined weight for a heavy helmsman/light crew team is modest over a light helmsman/heavy crew team, however it should be recognized that the heavier total combined weight crew will produce a longer and more stable immersed hull form.”
Hence the basis for devising a weight limit in the first place. Now, this conclusion is hardly a revelation to the sailors. We already knew that the heavier boats performed better upwind. However, the matter as to which ratio to utilize is still a matter of debate within our community. Using a 3.2/3.8 ratio this slight advantage can be adjusted for in a formula. However, under our current rule, we attach a 50% advantage (rather than the recommended 15%) to the light skipper/heavy crew combo with our 1.5 ratio.
The Aerohydro Study
The Aerohydro study was completed on June 15, 1994 and utilized the results of Nelson Marek as the foundation for crew and helmsman weight and positioning. Aerohydro tried to predict hull performance over the course of different crew combinations, different wind conditions, and even different race courses. The results were published in a variety of line graphs.
The study broke down the teams into nine categories or combinations.
Light helmsman (133 lbs/60.5 kg) and Light crew (133lbs/60.5 kg) = 266 lbs/121 kg total weight
Light helmsman (133 lbs/60.5 kg) and Medium crew (200lbs/90.7 kg) = 333 lbs/151.2 kg total weight
Light helmsman (133 lbs/60.5 kg) and Heavy crew (267 lbs/120.9 kg) = 400 lbs/180.4 kg total weight
Medium helmsman (200 lbs/90.7 kg) and Light crew (133lbs/60.5 kg) = 333 lbs/151.2 kg total weight
Medium helmsman (200 lbs/90.7 kg) and Medium crew (200 lbs/90.7 kg) = 400 lbs/180.4 kg total weight
Medium helmsman (200 lbs/90.7 kg) and Heavy crew (267 lbs/120.9 kg) = 467 lbs/211.6 kg total weight
Heavy helmsman (267 lbs/120.9 kg) and Light crew (133lbs/60.5 kg) = 400 lbs/180.4 kg total weight
Heavy helmsman (267 lbs/120.9 kg) and Medium crew (200lbs/90.7 kg) = 467 lbs/211.6 kg total weight
Heavy helmsman (267 lbs/120.9 kg) and Heavy crew (267 lbs/120.9 kg) = 534 lbs/241.8 kg total weight
Hull speed was predicted over a range of 6-16 knots and plotted over a triangle race course and a windward leeward course. All the graphs looked similar. They showed significant advantage for the lighter teams at the low end of the wind range and significant advantage for the heavier teams at the higher end. All of the performances merged at 9 knots. Essentially, the study established no advantage for any weight combination when the wind was at nine knots regardless as to the race course.
Much of the study is useful to confirm some assumptions that we already know: less payload, teams are faster when the wind is low; more payload, teams are faster when the wind is higher. Since we now have a weight limit, analyzing all nine of these weight combinations is not necessary. We should only really focus on the combinations that we effectively operate under now.
Light helmsman (133 lbs/60.5 kg) and Heavy crew (267 lbs/120.9 kg) = 400 lbs/180.4 kg total weight
Medium helmsman (200 lbs/90.7 kg) and Heavy crew (267 lbs/120.9 kg) = 467 lbs/211.6 kg total weight
Heavy helmsman (267 lbs/120.9 kg) and Medium crew (200lbs/90.7 kg) = 467 lbs/211.6 kg total weight
Even if we drill down to these three combos, it is still a little too broad. Most light helmsmen will be around twenty pounds (9.1 kg) heavier under our current rule, and the medium helmsman is probably about twenty pounds (9.1 kg) lighter. Our current teams are operating in a range of about 45 lbs./20.5 kg in total weight from 420 lbs./190.5 kg to 465 lbs./210.99 kg.
So, if you plot these three teams, you see that the two teams with the exact same total weight almost perform identically regardless of wind strength or race course. Only the Light Helmsman and Heavy Crew combo significantly deviates. This team has an advantage under nine knots and a similar disadvantage over nine knots. The disadvantage is because they are sailing a significantly lower total weight; 67 lbs. less to be precise.
What the Aerohydro study supports is threefold:
It is important quantify these measures; it helps put the debate into perspective. Since we essentially race windward leeward courses, I will focus on that single graph. The study utilized a ten nautical mile course. In addition, since the advantage is inverse when the wind velocity is fewer than nine knots and appears to not increase after 12 knots, I will examine the differences only at 12 knots.
Total range, from the faster team Heavy Helmsman to Heavy Crew to the slowest Light Helmsman with a Light crew, is three minutes and thirty-one seconds over a ten mile course. I think we all have been three minutes and thirty-one seconds behind at some point… that is a long way my friend.
However, when you apply the study to our current rule, the advantage is quite small. We can do this by only looking at these three teams that essentially comply with our current rule:
Light helmsman (133 lbs/60.5 kg) and Heavy crew (267 lbs/120.9 kg) = 400 lbs/180.4 kg total weight
Time to complete 10 mile course = 7771.5 seconds
Medium helmsman (200 lbs/90.7 kg) and Heavy crew (267 lbs/120.9 kg) = 467 lbs/211.6 kg total weight
Time to complete 10 mile course = 7725.3 seconds
Heavy helmsman (267 lbs/120.9 kg) and Medium crew (200lbs/90.7 kg) = 467 lbs/211.6 kg total weight
Time to complete 10 mile course = 7740.8 seconds
It seems quite odd or maybe laughable that a study proposes to reduce boat performance to a matter of seconds over a ten-mile course but Aerohyrdo puts a lot of foundation behind their results. (The study and data is available from the ISCYRA office).
If we only use these three teams, that range is reduced to 46 seconds. The study could use some further refining. Since the teams are a little heavy at 467 and light at 400, (our current rule really puts our range more like 465 to 420) I proportionally reduced the difference to about 26 seconds.
It appears the weight limit does a fairly decent job at reducing the advantage of a heavy team at 465 when compared to a lighter team at 420. If you looked closely though, the medium helmsman paired with the heavy crew did complete the course a little faster than the heavy skipper and medium crew. This fact would support the necessity to utilize a formula to account for the more effective weight placement as noted in the Nelson Marek study.
However, it only accounted for a fifteen second advantage over ten miles. This difference seems more in line with the 3.2/3.8 ratio proposed by Nelson Marek than the larger factor we use in our current weight limit formula. Nonetheless, our formula, as it’s written now, appropriately slows down the medium helmsman quite precisely and rather fairly.
If a change was made that would reduce this effective range from a 40 lbs. range (about 465 to 420) to a smaller spread of say 20 lbs., the impact might not be huge on the race course (probably cut another ten seconds and put all three teams on equal footing, according to the Aerohydro Study) but it may well help drive more participation.
Participation
As noted above and clearly articulated when our rule passed, we would most likely lose some level of participation from our sailors that could not find ways to comply with the limit. Who are they?
Most of us lost weight, got healthier, paired up with teammates that fit within the rules… we are the minions. Not much changed for us.
Well, we also lost a few heavy skippers and some super heavy crews that could not comply or pair up with an appropriate crew. This impact has been discussed at length and was part and parcel of a lawsuit that was filed in the United States. We never really had many light crews but some of these sailors found skippers to sail with and created teams that weren’t viable in the past, so we probably picked up a couple sailors on that front.
But, we may have also lost a few “little skippers” that may be under the impression that the formula put them a disadvantage. Well, as the studies determine, there is a slight disadvantage, but not greater than 26 seconds over 10 miles. Hardly worth missing out on the joy of racing a Star boat. Maybe, we can tweak this rule and bring a few more back into the Class.
Possible solutions
Flat weight limit: A flat weight limit is interesting because it seems to simplify the rule, make it easier to understand and apply. However, it would undoubtedly decrease participation as heavier skippers would no longer be able to compete with their current team and find a new crew about 20 lbs. /9.1 kg lighter. Conversely, the flat weight limit would raise the lower end of the formula up from about 420 lbs./190.5 kg to 440 lbs./199.5 kg and would allow for lighter helmsman to be more competitive. However, the flat limit doesn’t account for the 3.2/3.8 ratio conceived by Nelson Marek and would provide a slight advantage to the smaller helmsman; kind of like jumping from the frying pan into the fire. Also, as a Class we should encourage participation on both ends of the spectrum. Finally, we tried to pass a flat weight limit last month; we set the limit at 418 lbs/190 kg and it failed. Maybe it was too low?
No rule. I don’t think there is much support for this option.
Hybrid: How about a hybrid of the current formula and a flat weight limit? Impose a flat weight limit of 440 lbs./199.5 kg (or whatever number makes sense) unless the skipper weighs over 220 lbs./99.8 kg then apply the current formula. The result is an easy number to calculate for most, levels playing field for all teams by reducing range of total weight from forty to twenty pounds, maintains current teams and increases participation by allowing some heavier crews to compete.
Modified formula: A modified formula is supported by the two studies from 1994. The formula ratio (3.2/3.8) would be lifted out of the Nelson Marek study and applied, the range would be much tighter, about 20 lbs./9.1 kg, the only issue is to determine where to drop that 20 lbs./9.1 kg range… 440 to 460, 430 to 450, 420 to 440, 415-425, etc…
I will see you on the race course; I will be about 26 seconds behind you.
