Freundeskreis Klassische Yachten

The KLR – Formula

(Developed 1994 by Enno Thyen, Freundeskreis Klassische Yachten, Germany)

klr-formel.gif (3987 Byte)
KLR = Klassiker-Rennwert

L = LOA [m]
LWL = LWL [m]
B = beam [m]
T = draft [m] (including centerboard)
V = displacement [t]

All these measurements should be taken from the design if available. In the case of serious alterations the actual measurements should be taken.

S = Sailarea (effective)

Note: Generally the Sailarea is the average of the area which is carried upwind in moderate winds (above force 4) and the area in light winds, mostly using a genoa.
For example: a cutter-yawl :
S = 125 m2 (for all sails the effective area is used)

cb = factor underwater and keel-configuration
(centerboard 0.97; usual long-keel 1.00; separated rudder 1.03)

r = rigg-factor
(gaff 0.95; wishbone 0.97; ketsch 0.98; bermudian sloop, cutter, yawl 1.00; modified and not original high-tech-riggs up to 1.05 on the decision of the race-committee)

s = spinnaker-factor
(not using a spinnaker will normally give a bonus of 3% depending on the kind of the course, in this case s = 0.97)

It is understood, that the calculation generally bases on the expection, that the yacht carries sails, which complie to the rigg-measurements P, E, J, IG (see IMS-rules). Spinnakers should be „original“ in size. This means that carrying a monster-spinnaker compared to the „rule-spinnaker“ should be penelized by adding 1 or 2% extra (s = 1.01, 1.02) depending on the amount of the extra-width. As a responce to the dicision carrying a spinnaker or not it is suggested to give a bonus to the yacht without spinnaker of 3 % (see above). The dicision has to be made on the entry-form at least 72 h before the regatta.

The rule was used for 6 years in all Baltic-races organised by the Freundeskreis Klassische Yachten in Germany (Laboe 200 entries, Flensburg 160, Kiel 100) . It is also used in Norway (Europe Week 2000) – with good experiences as I know so far. The KTK did further developement on the rule in way of factors and exact determinations about how to measure the sail areas.
The results, calculated by time on time (), are very reasonable. It was shown, that very different yachts can be compared. The rule is very well accepted by the competitors.

Meanwhile the formula is used in the field of Yardstick, a yery popular German handicap-system. Yardstick is an empiric system, so you have the problem to give a rating for a new and unknown yacht (the same problem we had and have on our classic regattas whenever an unknown yacht appears). Our local yardstick-committee (I´m one of the 4 members) usually gives a certificate for these new boats and the KLR-formula is an accepted help to get the „starting figure“ beside a comparison to other similar yachts. The formula has shown being able to hit existing and proven yardstick-figures of many of the GRP-yachts on the point.

Space for further developement is given by the settings of various factors and I would like to introduce a propeller-factor „p“ with 1.00 using a usual 2- or 3-bladed fixed propeller and 1.01 without any propeller (racing-classes). In principle the formula gives a very acceptable idea of the yacht´s performance, regardless to the state of originallity, maintanance and condition. Only very few datas are needed – the formula is quick, simple and the owners are satisfied. The formula doesn´t give any motivation for tuning up classics with carbon masts and kevlar-sails, because we would penalize such features by setting reasonable factors (i.e. rigg-factor r), which in principle should refer at least to the yacht´s actual performanance. But in this way it´s no problem to let them sail all.

For the future we want to avoid a complicated practice using a rating-system for we have very good experiances with our „simple system“. Every additional yacht´s data or dimension and every additional factor will cause more work, more control and it isn´t for sure, that you´ll obtain better results. We don´t want to have measurements at all because our Baltic-fleet consists of more than 300 yachts.

We don´t want to mix the yacht´s observable sailing performance and the state of originallity as fas as it doesn´t influence the performance. We think there are more efficient strategies to reach the aim of preserving vintage and classic yachts.

In some cases we adjusted ratings after an evaluation of several racing results, because it was shown, that some yachts could´t reach their ratings or they were really faster than calculated. Without any doubt you can have two designs with exactly the same datas used in the formula which may perform quite different. The slower boat isn´t neccessarely a bad boat because it may have other advantages than being a good racer.
The biggest number of our yachts race with their calculated rating and we have very few trouble.
Each organizer of a classics regatta-event will decide whether a yacht is „classic enough“ to take part in the races, the racing committee is responsible for the starting-groups and occasionally for the settings of the factors of the KLR-formula. Mostly the KLR-figures can be taken from the existing list for more than 300 yachts. We will establish an FKY racing committee, whose tasks will be: Maintaining and publishing the KLR-List and the FKY Racing Rules and setting the rating adjustments.


Using the KLR-formula separates racing from the judgement over items like authenticity, originallity, state of maintanance, degree of original substance and so on. For these (also very important) items we have for example a restoration prize.
Using KLR is very simple, we don´t have measurement-certificates and we don´t want them.
KLR doesn´t need complicated measurements, in some cases we have to ask and to explain to get the „right“ datas (some owners will give the measured sail-area which is less, others are not shure about the yachts displacement).
After 6 years in use without changings we notice a high degree of acceptance.
The KLR-formula has no type-producing character like the well known rules RORC, CCA, IOR, mR ever had. That means that no type will get notable advantages or disadvantages. It is a formula to get ratings for an existing crowd of very different yachts, spread over the various categories of types and spread over about a hundred years.