The year is 2012 and in terms of the competitive racing of very large yachts the closest thing that we have to a true modern Maxi division is the J Class. The level of performance investment found in the modern J Class fleet is without parallel, with the smartest technical minds in sailing well resourced in their efforts to outflank rivals. Time for Seahorse to take a closer look…

SOME MODERN HISTORY – Jeroen de Vos, Dykstra Naval Architects

J Class yachts are a product of the Universal Rule, which was first adopted for the America’s Cup in 1930. From 1930 to 1936 three Cups were sailed with J Class yachts, and in that time a total of 10 Js were built. But only three of them survived: Shamrock V, Endeavour and Velsheda. Currently, however, there are seven J Class yachts on the water racing under the umbrella of the J Class Association (JCA).

Dykstra Naval Architects have been involved in many modern J Class projects: the first refit of Endeavour in 1989, the refit of Velsheda in 1996, the refit of Shamrock in 1998, the refit of Ranger in 2005, the new build Hanuman (a replica of Endeavour II) in 2009, second refit of Endeavour in 2011, and the new build Rainbow in 2012.

From the client the ‘usual’ design brief is to design a fast and classic J Class yacht. Simple... not entirely. These clients want to race their yachts hard, but at the end of the day the same boats are also used extensively for cruising. So there needs to be a balance between the looks and comfort of the yacht and its performance, while it must also be manageable to sail.

What makes the biggest difference between cruising and racing mode for these boats is the sailplan. When racing, a J Class carries (very) large overlapping headsails, with a maximum LP of 130% and around 440m2 in area. But for cruising such huge sails are far too difficult to work with; they are also normally hanked on, which is not ideal for a small cruising crew.