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.