DEREK KELSALL, FRINA, on 45th. Anniversary of Toria's RBR Win.
Perhaps the most influential sailor, designer, builder and innovator in multihulls.

2011 is the 45th. Anniversary of the first Round Britain Race in 1966. The two handed, 2000 mile race was won convincingly by a trimaran called Toria, completing the circumnavigation of the British Isles a day ahead of the next to finish. If we look at the history, almost all of the multihull trends since, but also of some other fields, lead back to Toria and to that event.

This includes racing monos and even the French multihull interest, which exploded shortly after that time, has a direct Kelsall connection. The French have dominated the major races and multihull production since. Looking more closely, the influence of this active designer and innovator, continues today.



Multihulls at that time were the crazy fringe element in the eyes of the establishment yachties. Two years before the Round Britain, DK was the first to race across an ocean in a yacht without ballast, in the 1964 Solo Atlantic Race. The suggestions reported at the time varied from this trimaran will span two waves and break up, to some form of death wish. To put that into context, the two catamarans in the s ame race both had deep keels and lead ballast and hence were acceptable.

Toria was DK's first own design, the first foam sandwich yacht of note and the first multihull to win a major open offshore race. Also unique in being a designed, built, raced and won situation for DK. The Toria arrangement and overall design set the style for all that followed.

As we all know, trimarans have dominated all offshore records since and foam sandwich construction has become the preferred building materials specification for almost all boats.

Other winners followed to add to an amazing run of successes. Kelsall was involved as designer or designer and builder or as builder in almost all major race events over the next two decades. Amongst the many multihulls and monos were two notable mono builds; Sir Thomas Lipton to win the next solos Atlantic race in 1968 and 78 ft., GB 11 to be the first to finish in the first Whitbread Around the world race. Both were the largest sailing yachts in composites of the time.

NZ Design Office.

Today, the NZ Kelsall Design office is responsible for many projects around the world. Peru, China and Korea are the most active in terms of numbers and ongoing projects but other projects are underway in more than a dozen other countries. Most are catamarans but not all. There are three aluminium charter catamarans amongst recent launches.


Having pioneered the use of foam, developing and refining the handling of the sandwich materials became an ongoing interest and is still so today. KSS (Kelsall Swiftsure Sandwich) is the Kelsall build technique which is claimed to slash the build time without compromise of the final product. A quick look at how KSS tackles every task of building a boat structure, compared to the popularly promoted alternatives and the savings (a factor of 2 or 3 or more) are easy to see.

The “still leading” claim would be equally difficult to argue against. DK recalls reading in PBB in the mid 1990's that foam sandwich came into use in the mid seventies and the use of a full size mold table was a recent phenomenon. The Bruce Farr office was more recently credited with introducing light weight sandwich construction with their winning design for the Swiss entry into the Around the World race in 1985. Kelsall lightweight foam sandwich construction began in 1965. The first Kelsall table was in use in 1973. The first Kelsall Around the World winner was in 1973.

If looking for a forerunner of the current AC catamarans, with rigging below the central structure and the curved foils, they can be found on a 63 foot Kelsall cat in 1980 and curved foils on Kelsall trimarans and on a Kelsall speed sailing machine at approx. the same time.


Resin infusion is the in word of building in the past ten years. After so many years of handling the sticky stuff, DK describes Resin Infusion as “the Magic”. The KSS workshops and the KSS projects have played a major role in spreading the resin infusion message – particularly in NZ, OZ and the US. For about five years a Google of Resin Infusion brought up Kelsall Catamarans in top spot. One NZ resin supplier made no secret of his skepticism, before an open day at a Kelsall project attracted 70 boat builders from around the country showed the way.

KSS combined with the very wide experience of all kinds of craft bring the clients to Kelsall. He is certainly the most active of the early multihull designers with a place in the history of the modern expansion of boats with two or three hulls. Two names spring to mind from the v. early days of the modern multihull scene. They are fellow Welshman James Wharram and Californian Arthur Piver. Both put a lot of multis onto the water, and James is still active, although neither could claim the wider influence on racing or build materials and methods or with monohull connections.

Other now well known designers, such as John Shuttleworth, started with Kelsall and a long list of famous racers sailed Kelsall designs. Raph Farrant, Tony Bullimore, Nick Keig, Chay Blyth, Phil Weld, Eugene Riguidel, Mike Golding all chose Kelsall designs at some stage in their offshore racing careers, collecting a lot of famous trophies.


A feature of the Kelsall activities is the KSS workshops, which are held from time to time in various locations. Mostly in US, Australia and NZ but have included UK, France and China. The workshops give attendees hands on experience of most aspects of custom boat building but also of resin infusion which was first refined for KSS and then adopted as standard for all Kelsall projects ten years ago.

The workshops appeal across the board, from the novice considering his first build project to the professional. Ten years ago, the KSS range were the first on offer with an in-house, fully refined infusion technique as standard.


The range of projects is impressive. Every size and style from a small day cat to 500 passenger ferries. At least five were largest of type at the time.


The Kelsall boats to be found in NZ or built in NZ give a snapshot of the variety.

KSS 54 - Cool Change.

This owner built, KSS 54 stands out in any harbour. She has twin freestanding wing masts which carry two mainsails, side by side. As a charter and live aboard cruising catamaran, she is a great success. Even the masts were built by Don and Marilyn Logan. She has covered more than 21,000 miles. In a recent 40 mile race, she stirred up a few controversies by out sailing a fully crewed, very successful, eleven foot longer race mono. Don and Marilyn were the only crew and the well used two mains were the only sails on board. Cool Change outperformed the mono on all points of sailing, including upwind and directly down wind. She is available for charter, which Kelsall strongly recommends – the experience of sailing such a unique, versatile and efficient rig is enhanced by the expertise and the hospitality of Don and Marilyn.

KSS p33 - Kaivitikat.

This 10m outboard powered catamaran is also an owner build project but starting from a KSS kit. She is also for charter, with space and survey for 18 passengers and 3 crew. Operating out of Athenree, the owner describes Kaivitikat as superb in coping with the bar at the entrance. The twin 60 hp outboards give a max of 20 kts. She is also for sale at this time (May 2011).

KSS p20 – Lindy.

This little cat brings home the Snapper. Twin 30 hp outboard get to the fishing grounds at about 22 kts and she is trailed home after each trip. Great fun.

KSS p82 – Bonefish.

This is a yacht at the other end of the scale. Ideal for expedition style fast cruising or charter. She qualifies as a super yacht in any comparison. Also for sale. Currently in Florida. Talk to the designer on this one – 82 ft.

KSS 70 - My Way.

At 70 foot this is luxury cruising at its best. One of the two American owners guessed that she had covered 75,000 miles over the past 6 years. She has visited hundreds of Pacific Island in two crossings, as well as around the World, including a very adventurous passage through the Gulf of Aden. Currently she is back in the Panama canal, heading back to home port, San Francisco.


The common factors are – Kelsall Design, KSS build and Sandwich Construction.

The Kelsall clients choose their projects from the wide range of standard designs available or contract for a custom design. Current custom design projects include four different designs between 60 and 65 feet, a performance pod cat, a house boat cat and a proa. Design numbers are over 400, and mounting, particularly into the larger sizes and into the more commercial fields.

Can any other designer equal this range of experience – multihulls racer, custom builder and designer? The adventurous sailor has many tales to tell. As builder, each project has its behind the scenes story. Each advance in the KSS build technique would fill a book.

Looking to the future, DK sees KSS adding many more designs and extending further into the larger craft and into commercial craft where the KSS advantages are even greater with size. Latest contract is for a superstructure for a large steel hull. The professional builders are producing part moulds, which are very effective in conjunction with KSS panels when more than one is planned. Modular assembly designs are afloat and in build, for another field with many applications, which adds another level of efficiency for the KSS boat builder. The DIY builders, where DK began,are not forgotten in this expansion. KSS = get the job done quicker (A lot quicker).

DK's right hand man is Liviu Armeanu, who has been part of the Kelsall design team for ten years. An engineering graduate, the office computer expert, who is also a Westlawn Yacht design graduate. Liviu obtained his masters degree in composites. 3D CAD and FEA are his metier.

Leading the way since 1965 and where others follow – there is only one name:
Kelsall Catamarans