A Comparison of the Measurement Rules Governing Racing in This Country and Abroad
Made by One of the Foremost European Yacht Designers

By Johan Anker

What is the object of a measurement Rule?
To promote yacht racing.

As hot competition is essential for good racing the rule must be able to satisfy a yacht's owner in this respect, and the boat the rule produces must appeal to the owner as worthy of his care and attention. In other words, a measurement rule today has a social as well as a technical problem to deal with and to settle satisfactorily if it is to have any chance of success.

The social side does not as a whole bring out divergent opinions, and as it is the technical part of the question that is most difficult to settle, it is this side that takes the greatest hold on our interest and attention.

As the two rules stand today, the Universal Rule (in use in America) is the outcome of experiences with measurement rules from the beginning of yacht racing till the present on your side, and the International Rule is the same on our side. They have in common the aim to offer the owner opportunity of racing, as well as a sound seaworthy boat for cruising purposes, if cruising should be desired. They are both trying to safeguard the owner from the designer’s wild experiments and secure him some value for his invested money.

But the way they try to do this is different.

The Universal Rule has one particular type of boat in mind - the type that the makers of the Rule preferred when it was formed.

The International Rule has no particular type in mind; it tries to give a just measure of the speed factors of any type of boat.

The quarter-beam measurement in the Universal Rule promotes a type, as a given percentage of the water line length is free; only where there is an excess of this limit does the quarter-beam measurement come into play; whereas in the International Rule bow and stern-girth are measured and added to the length, whether small or large.

The length measurement in the International Rule is calculated to correspond, and in most cases does correspond very nearly to the length the boat uses when sailing. The length measurement in the Universal Rule is the water-line length, when at anchor or dead still, the quarter-beam restriction acting as regulator or form.

Besides these differences, the two rules balance sail and hull measurements differently. The Universal Rule is very nearly a sail-measurement rule, while the International is a hull as well as a sail-measurement rule. It is this difference in the rules more than anything else that turned the tide at the conference at London in 1919, in favor of our present International Rule.

Where in your Rule the hull figures to such a small extent in the final outcome, it is evident that the hull under this rule will increase in length; and thus in waters where prevailing winds are stronger, the hull or racing boats gradually will increase in length, and become very much larger than boats of the same class sailed where winds are lighter. Because of this tendency in the Rule, the owners of racing yachts will for yet some years to come run the risk of finding their boats outclassed the second season, and they will always risk racing boats which are unevenly matched.

In the International Rule, where hull and sail are evenly taxed, this tendency is barred, because if the hull should be increased, the sail area would be hopelessly small, and vice-versa.

Now, let us consider what the two rules have told us in practice.

Universal Rule boats are constantly outclassed, although the Rule has been in force many more years than the International, where we all know of several boats racing with fame in spite of being from three to four years old. This is the strongest argument in favor of the International Rule, because yachtsmen do not like to go into class racing, when they can foresee that a costly built boat will be out of the game the second season. It is this sentiment that has created the numerous one-design classes on your side, instead of open class racing.

The International Rule has the virtues of the one-design so far that the boats are more evenly matched than in any other free rule, and yet competition in design is not barred. As to the shape or form of hull, the difference between the boats of the two rules is not so great as one would think.

One important factor that acts in the direction of equality is the same, or practically the same, stipulation of displacement to the length of water line in both rules. And one even more important factor is nature's laws. The sea and the water like to be treated nicely, and get obstructive when their secret laws are not taken into consideration. So, although apparently the boats built under them may be alike, there are differences, especially in the above-water body.

From my experience in designing and building to both rules, I know that I can modify an International form into an Universal, thereby reducing its seaworthiness and inside headroom, and I can alter an Universal form to fit the International and thereby increase its seaworthiness and cruising qualities.

The above is my technical valuation of the two rules. Now to the social side of the problem.

From this angle the rule that offers the hottest competition and greatest opportunity for racing must be preferable.

The International rule thus would be preferable even if it was an inferior rule it is International.

Sport has a mission to the individual. International sport has the mission to bring individuals of different nations together. The great sufferings of our present time are caused by a lack of understanding. More international intercourse in all branches of human life, would, perhaps, have saved us from the last war.

INTERNATIONELLA MÄTNINGSREGELNS REVISION.

Seglarbladets enquète.

Johan Anker

Oslo, May 1915

In the beginning the object of a Rating Rule was to determine a boat’s size, length, beam and draught, with volume as result, e.g. the Girth Ton Rule, which classed the boat according to tonnage.

Experience showed that the speed of a boat is not only dependent on the size of the hull, but also materially on the driving force, the sail area. The measurement of a boat’s volume was therefore given up, and a boat was classed according to its “racing-length” by measuring the length on the water-line and the sail area, e.g. Rule of the Length and Sail-area. However, many years did not elapse before it became clear that there were other speed-factors. The size of the hull below the water-line grew smaller and smaller, while above the water it exceeded all reasonable limits.

The next change was the introduction of under-water capacity as a minus factor by rating d. – the difference between chain and skin girth – while at the same time the L.W.L. was measured 5 cm. above the actual L.W.L. and the L. o.a. was limited to 150% of L.W.L. Copenhagen Conference Rule. Typical representatives for boats of this Rule are “Princess Margaret” and Brand II”. Both remind one more of a box than of what one understands by a boat.

But the box-shape was not popular, and the sail area became enormous: “Brand II” had 150 m² and under this Rule we should soon have reached 200 m² for a nine-metres. So when the time came when the Rule expired, it was supplanted by the International Rule, which in principle is the same as the Copenhagen Conference Rule, with the addition of stern and bow dimensions, the intention being to keep the fullnes of the hull above the water-line fore and aft within reasonable bounds.

Contemporary with this development in Europe (England has almost gone on the same line as we in Scandinavia and Germany) is the similar development in America, though the means employed were not identical.

The present American Rule is framed with the same ostensible object as our International one, and merely uses other factors to seek to attain the same desired result.

If I am to express an opinion of the International Rule, I cannot forbear mentioning this line of development, which is so closely connected with the development of the different types of boats; for I am of opinion that every rule must be regarded in the light of the foregoing one, if we are to judge of its value, and seen in that light it is easy to understand that our present rule is far better than any earlier one, and better than any other now existing.

It is built up logically and consistently on the experience we have gathered from earlier rules, and in the main it has proved, in face of the attacks we have exerted ourselves to direct against it – it being our pleasure to try to upset every rule – extraordinarily good.

As the first and foremost object is to satisfy yachtsmen’s needs, the cry for a mathematically correct formula is laughable, just as laughable as to demand boots made on a mathematical last.

One thing will soon strike those who compare the earlier rules with the present one, viz., that the aim is increasingly to measure the speed, or more correctly sail-power, than the real size of a boat, and if we could imagine a mathematically correct formula, framed with the object of measuring the speed or sail-power, then all speed-factors would have to be taken into consideration. In other words, we should frame an ideal handicap-rule. Helmsman and manoeuvering alone would matter, the boat might be what it would – and the mathematically correct rule would be evolved when a barge could be matched against the finest racing-craft built.

To be quite just to the International Rule, we must not forget to distinguish between the Rule itself as a measurement rule, and the scantling-rule introduced at the same time.

It is, of course, difficult to decide how great an influence the scantling-rule has had on the shape of boats, since no boat can be built without conforming to the usual regulations for dimensions; but I am sure that the scantling-rule has had a far greater influence on the shape of boats than was at first anticipated, and more than is generally thought. This influence has been the more noticeable as it works in the same tendency as the Rating Rule itself, in that it also favours a large displacement.

But though I am an ardent supporter of our present Rule, I am naturally not blind to its weak sides, which I think can be corrected when the time for alternation arrives.

A more happy combination of the separate factors seems to me to be desirable; but I deem it inexpedient, now to go into the details of any such change in the Rule.

We have already, in truth, gained no little experience in past years; but we shall know more when the time for a change is at hand, and shall be able to judge more confidently than now. But one thing I should like to say: The sail area, as it is now, is too large, and the stability uniformly too small in all classes.

Johan Anker.

        1933 - From "Kongelig Norsk Seilforening 1883-1933" (the first 50 years of the KNS)