originally published in Multihull Review magazine (UK) 2007

In my previous article I recommended that those looking to have fun when sailing offshore should buy a performance cruiser, probably around 10m long, that complies with the Recreational Craft Directive Category B.

After thinking about it for the last couple of months hopefully you're now saying "Yes, that sounds like a good idea. I've always wanted a fast boat, bigger than a micromultihull, but not too large, as I don't intend living on board and only want to sail with at most three or four crew."

As I am a catamaran designer I hope you're also thinking "I don't really fancy a trimaran. I want more privacy and more deck space than a trimaran can offer, and I'd prefer a boat that stayed dry and didn't heel too much. But I still want the speed of a F28 or a Dragonfly 920."

Indeed the Farrier and Dragonfly trimarans have pretty much sown up the market in this size range, but that's not to say a catamaran can't be as fast. The last time I raced I was crewing on a F31 in a regatta in British Columbia with 16 other multihulls, all but one of which were Farriers. Yet, despite the high tech Cuban sails on some of the trimarans, it was a 35ft home built catamaran that won most races.

Before discussing the boat you see here, I'd first like to consider how we could encourage more performance boats to be built. Fortunately, just by commissioning this series of articles, the editor has ensured that people start thinking about the concept.

Often racers and racing start a trend. They certainly generate publicity and make people think, "Yes, why not buy a boat like that." There's no denying that the Micromultihull rule helped sell a lot of Dragonfly and Farrier designs.

It may sound like putting the cart before the horse, but if no races are organized then few people are going to buy a new performance cruiser. You may spend your first season burning around beating all the monohulls, and, while nipping over to Cherbourg for lunch and back home for tea is great fun for a while, sooner or later it will begin to pall, and you'll want to race.

As I said before, bigger boats are less suited for one hour round-the-cans races; you can use a beach cat or micromultihull for that. However, to race offshore you really need a boat over 9m long, so it looks like these 10m performance cruisers would be ideal for weekend coastal races, like the UK's Round the Island, Sweden's Round Tjörn Race, France's Tour de l'Ile de Ré and Canada's Swiftsure.

These all have the added attraction of lots of monohulls to beat. Even so, these are all long day-races rather than overnighters. It seems there are very few offshore races anywhere in the world for people who want to race just at weekends.

So it is 100-150 mile races that multihull racing associations should be thinking about organizing if they are to encourage more of the larger multihulls to race. Agreed, there are always the Round Britain and Fastnet races, but these are too daunting and time consuming for most, so will never have mass appeal.

Having said that, one can't just organize an appealing race and expect people to come; the old adage, "have fun, race hard and never mind the results" is all very well, but potential entrants must know that they have at least a chance of winning.

Thus getting the handicaps right is vital for successful racing. Although organizing races is not part of a designers brief, maybe suggesting a suitable rating rule is.

So here's my starter for ten.

If the fleet is not one design then races must be held using a handicap system, which is normally based on either a personal handicap (eg PY) or a rating rule. Most people favour the latter. The problem with a rating rule is that if it is too all-encompassing it can't be fair to all.

So these days the most successful rating rules are what are known as "Box Rules". In other words, performance limits are first set by having maximum and minimum parameters of the main dimensions - length, sail area, weight etc. Then handicaps are further refined by the rule. Of course results will still be corrected according to rating, but if the ratings are all the same then one has boat for boat racing - both the America's Cup and Volvo Race use this Box Rule concept.

A Box Rule also encourages boats to be of similar proportions so they are more likely to sail in similar tide and weather conditions and all finish close together. Close racing adds to the fun and excitement and that's basically what it's all about.

So, my suggestion for a performance cruiser multihull Box Rule would be to base it on: " Rated Length 9.8m " Rated Weight of 2.2T " Rated Sail Area 53 sqm

The resulting rating would thus be approximately 1.2 - 1.25 under MOCRA, or a Texel No of 110 approx, or NWMA of -15 approx.

(As you can see, there are currently at least three major rating systems in use world wide. The Multi2000 rule, as used in France and elsewhere, is essentially the same as the Texel rule. It seems different multihull associations only try to cater to the boats sailing in their local area. Maybe a rule designed round a specific style and size of boat could be truly international.)

" All boats must comply with the RCD Category B. (That's basically the "Offshore" category and assumes ocean crossing potential. Boats should not too light (as Category C boats tend to be) for we must allow conventional grp production boats to be competitive. Furthermore, light boats have limited load carrying, whereas these boats are supposed to be performance cruisers, not just racers.)

" The rule must include existing boats that meet the spirit of the class. (Thus boats like the Dragonfly 920, Farrier 32, and Dazcat 10m should comply but not the Lightwave 32 or Raider 30, as I think both are too racy to be considered as most people's idea of a cruising boat.)

The interior accommodation requirements are probably the most important factor to ensure a true cruising boat, unfortunately they are also the hardest to quantify.

So my suggestions are for boats to comply with the spirit of the rule and to have: " Minimum 4 berths, all useable at sea " Minimum fixed 2 burner stove, fitted sink, 0.2sqm additional worktop area, plus adequate stowage " Eating table useable at sea that can seat four " Separate chart table minimum 600mm x 450mm " Headroom minimum 1.75m over 0.9sqm (total) cabin sole " Fitted toilet in separate compartment "

An engine that will drive the boat at 5.5knots minimum in flat water "

All measurements and ratings to be in the public domain

" No individual boat sponsorship. Sponsors can only support the class as a whole.

I also recommend that there be no overall winner, instead 1st catamaran and 1st trimaran should have equal billing. (The class should be an "owner - driver" class, so that "ordinary" sailors feel they are in with a chance.)

Finally, I think the class could be called the 10metre rule, or 10MR for short, which for some will no doubt bring back old memories.

What makes a 10MR performance multihull? Obviously all designers will have their own ideas, but some basic naval architecture concepts always apply; whatever ones design philosophy.

As we know, there are three main types of catamaran.

First, there are those with a full bridge-deck cabin, like my Eclipse design. But we have already agreed that these boats have too much accommodation and load carrying and although they can be fast, most don't have enough performance to be a suitable 10MR boat.

Second is the open deck catamaran, which can be very light, so there should be no problem with performance. But, having cruised open deck boats thousands of miles, I know that they are not very comfortable, and that the crew is always exposed to the weather. Furthermore couples want a double berth, while everyone wants to sit round a table rather than sit in a "train corridor."

So the third type of catamaran, one with a central cuddy, seems like the ideal performance cruiser.

Although I have designed a number of cuddy boats over the years (Wizard, Gypsy, Romany, etc.) I don't actually have a larger, performance, cuddy catamaran in my design portfolio.

Now I don't want this article to be just a showcase for one of my designs, but I did need to draw something so you would get an idea of what a 10MR catamaran might look like.

So I started sketching a new 10m design, called Mustang. There is still a lot of work needed before the design is finalized, but even so, the more I thought about it the more appealing it appeared. So I will continue to work on the design in the coming months.

The overall concept is typical of my more recent performance designs. The cuddy keeps both weight and windage down, and is an efficient use of interior space as none is lost by the need to keep passageways down into the hulls clear. The crew are well protected, yet moving around on deck is easy and there is no need to get near the gunwales when sail handling. The knuckle in the hull adds interior room, reduces slamming and deflects spray.

The hull has lots of flare at the waterline, where it's most needed most, as the boat will then have a smoother ride through waves and will carry a load better. And it is V'eed back to just aft of midships, thus helping reduce hull pounding in waves.

The working deck areas are of course flat, but other decks and the cuddy are rounded, not just for windage reduction, but also because, surprisingly perhaps, it's easier to laminate curves than chines

. Standing headroom is important in both the shower/heads compartment and the galley, but both of these can be under a sliding/lifting hatch. Elsewhere headroom isn't that essential and just adds more windage and weight.

Sail lockers forward on each side are for efficient racing sail changes, while for safety and to keep the ends light Mustang features large watertight compartments and crash bulkheads.

The biggest change I've made to my designs over the years has been to the rig. Mainsails have got bigger and genoas smaller. That's mainly because of the better sail hardware, sail cloth and battens now available. The smaller genoa loads the rig less and when sailing off wind the big mainsail/spinnaker combination offers more downwind area than the smaller mainsail/spinnaker does.

No boat can ever give good performance with cheap cross cut sails. So I would expect serious racers to have two suits of sails: The racing high tech, square-top rig shown here, and a smaller rig with cut down roach for cruising.

Construction would, of course, be in vacuum bagged foam with non-crimp multiaxial glass. Interior finish would be basic as I've found a lot of unnecessary weight goes into making the boat look pretty.

I have already had discussions with an experienced multihull boatbuilder, well known to UK sailors. He's keen to build boats, and is aiming at a base price of GBP75,000 ex sails.

We just need an investor and some orders.

If you are a boatbuilder or designer who has a boat you feel should fit the new class, or if the idea of racing a boat like Mustang appeals, then please contact the editor. We would of course also welcome any criticism of the idea!

The new Multihull Review web forum is now open and just waiting to be filled with your comments and ideas. So over to you!