If the boat at the right looks familiar, there is a good reason. It is designed to the same (but updated) measurement rule as the famous J-Class. It's an M-boat, about 20% larger than a 12-Metre, considerably more powerful, and a true racing yacht capable of housing a nice interior as well.
The modern M-boat is a true racing boat, capable of the same kind of performance that one expects from a J-Class or 12-Metre: a powerful boat, very seaworthy if properly equipped.
The modernized rule to which this boat would be built incorporates a number of features to limit development and maintain a classical look. Speed improvements in the class will usually be small and hard to come by, and the racing should be very close. The boats will probably have a longer-than-normal competitive life because of these restrictions, and will remain beautiful, as well as functional, boats. Yet, because this is not a one design class, the fun of design development and equipment experimentation will remain.
A modern M-boat will also have the power to permit a fine interior. This web site shows a couple of the many possible variations which can be used, without a devastating impact on performance. Originally we thought it might be best to permit either an interior or a set of fixed weights approximating an interior. Watching the development of the new J-Class, however, has made it clear that there is a general preference for a boat with a good interior. With this in mind, we selected a modest interior suitable for a crew of eight people for a weekend. This provides a nice interior, but also leaves good racing performance intact. The rule specifies the requirements for this kind of interior.
The Arrangement Plans in the Arrangement Drawings section of this site show a somewhat unconventional approach to the interior, carried out in two very different manners.
In these layouts the main influences have been the desire for a nice owner's cabin aft, and the desire to have the small forward deck house to permit that hatch to be open often for good lighting and ventilation, which would be difficult to achieve if this were a deck-mounted hatch prone to take quantities of water below any time some solid water came over the side in a big seaway.
For cruising, the boat's large fore triangle and 80% rig allows a good distribution of sail between main and fore triangle, making it easy to balance the boat. With the large fore triangle, adequate cruising performance can be achieved without the use of overlapping headsails, making short handed sailing -- always tough on this big a boat -- considerably easier. The performance loss should be fairly small.
The M-boat in the accompanying comparison drawing and chart (dark gray) looks small compared to a J-boat. It is about 20% larger than a 12-Metre, though (light gray). The M-boat is, while considerably smaller than a J-boat, nonetheless a big, powerful boat, able to point up high and still drive through even steep chop and seas.
The Universal Rule, to which the M-Class is built, and the International Rule, to which the 12-Metre is built, use the same displacement formula, but the larger M-boat has a higher ratio of sail to displacement and sail to wetted area. This makes the M-boat both quicker and more powerful.
While the rated sail area of the M-Boat is retained from the earlier rule, the aspect ratio is considerably higher, making a more efficient boat to windward, and also making the sail plan much easier to fit on the deck. This would normally make the symmetrical spinnakers narrower, but we've added to the spinnaker pole length, which will prevent the spinnaker from getting narrower and thus minimize any oscillatory tendency. For cruising, those on board can readily opt for an asymmetrical gennaker instead, greatly reducing the complexity of tasks involved in handling the big spinnaker.
Here's some typical dimensions* for a J-boat, M-boat under the new revised rule, and a 12-Metre:
* The information in this table is based on hypothetical boats to each rule, but influenced more than anything else by the designs of our own J-Class design, our M-Class development program but especially the "demo boat", and our 12-Metre design. There will be more on the J-boat, which we call "Morning Star", on the Fladlien & Associates web site.