Ed Dubois is right in the thick of creating a new 58m sloop with the Royal Huisman Shipyard in the Netherlands. And as is being seen elsewhere in the superyacht market, outright performance is steadily making its way ever higher up the scale of owner priorities…

Design 405 – 58m sloop
Dubois Naval Architects are delighted to be designing this exciting new yacht for a highly experienced owner who has competed at the highest level in offshore and inshore yacht racing. It was clear from the outset that his priorities were exciting in so far as he wanted to combine high performance with completely reliable and also comfortable world cruising ability, and for the yacht to be capable of remaining independent for long periods of time.

From the outset Royal Huisman Shipyard were chosen and we, as designers, saw this as a great opportunity to further cement a relationship with this most prestigious and exceptional yacht builder.

The design has drawn on our high level of experience over many years, beginning with racing yacht design success and carrying on with the emergent, and then booming, superyacht design era through the 1990s and 2000s. In particular, our experience with such yachts as the 66m Aglaia and more recently the 46m Ganesha (launched in 2011 and 2013 respectively) has proved a secure benchmark.

As is becoming increasingly the case with modern performance superyacht design, we duly embarked on a research programme including Computer Fluid Dynamics (CFD) analysis and the tank testing of a large-scale (1:10) model, using the Wolfson Unit at Southampton University. The details of this research remain confidential; however, the aim centred on developing and refining the various areas of 1) hull form (the best balance of reduced wetted surface versus stability), 2) performance in waves and 3) refinement of keel and bulb shapes. A fourth area of research was to investigate the comparative benefits of single and twin rudders. Structural analysis was a fifth focus for attention, including longitudinal strength and bending.

Designer Nigel Irens and rig architect Torbjørn Linderson take note of some of the lessons from their latest joint creation… the high-tech composite 78ft cat Allegra, launched recently by Green Marine

Design – Nigel Irens
After 35 years spent trying to make ocean racing trimarans go faster than the competition you get a bit obsessive about keeping the weight of a multihull to a minimum. It’s not complicated – righting moment is the product of multiplying half-beam (centreline to centreline) by displacement. Unsurprisingly, performance is maximised by achieving a high RM through pushing half beam up and displacement down, and doing that better has been the key objective in achieving radical performance improvements over the years.

Where cruising multihulls are concerned the story is very different, and an abundance of weight is obviously inevitable from the outset. In fact, the weight spirals upwards. As the desire for more living space and a higher degree of comfort increases, so a heavier and more powerful rig is needed, together with the machinery and deck gear necessary to power the whole thing up. Against this background, promising a catamaran that can offer both high levels of comfort and great performance seems a bit rash, but there is a third element that can change the game and that is budget.

For decades cruising catamarans have been perceived as the low-cost way of taking as many people to sea as possible. They are usually shallow drafted, they sail more or less upright, and, yes, you can see out of the windows. Performance has to take a back seat because it is an attribute that is usually too expensive – both to buy and maintain. The charter market, for example, in which many of these boats serve, will simply not pay the premium needed for high-performance sailing.

Now, however, a relatively new market is beginning to open up. Green Marine, who built the recently launched 24m Allegra, have coined the phrase ‘Premium Catamaran’ to describe such boats. Pioneers like Gunboat have been paving the way over the past 15 years, but now the cat is, so to speak, finally out of the bag, and it looks as though this fledgling market is going to see some interesting developments in the coming years.