Interview with Hanneke Boon of Wharram Catamarans

Diane interviews Hanneke Boon who is a long time partner of James Wharram and designer of Wharram. She gives a historical recount since the 1938’s of catamaran design and sailing! She talks about her opinion of modern cruising catamarans and how Wharrams are different and really better for cruising.

She and the team at Wharram are still busy selling plans to people all over the world!

Wharram’s book of memoirs ‘People of the Sea’:

Please enjoy the recorded interview available below and the transcript with many photos.

Today, we’re really happy to be here speaking to Hanneke Boon, head of James Wharram Designs. Hanneke also co-designed the boats alongside the legendary multihull pioneer and designer, James Wharram. Hanneke, welcome. I’m wondering if you could tell us a little bit about yourself, and your role at Wharram.

I’ve spent most of my life with James, actually. I first met him when I was just 14. My father was interested in his boats, this was in the 60s, when James had fairly recently done his voyages. He’d started selling designs in North Wales and my father wanted to go and meet this unusual character he’d read about. We ended up on the beach where James was living on his catamaran “Rongo,” which he did his first crossings on.


We bought a set of plans for a 22-footer and then we built that in Holland. I’m originally from the Netherlands. We built that boat over about a year, and then we got to know James and Ruth very well during this period. We did further trips to England to help them build their previous boat. It was a 51-footer called “Tehini.” That was being built out in the open with hand trowels in North Wales. This was 1968-69. In fact, a lovely film on YouTube about it, people can find out on our channel.

Tehini Launch

Can you tell me the name of the film?

It’s called “The Building of Tehini.”

Okay, great!

“The Building and the Sailing of Tehini.” It’s on the James Wharram Designs YouTube channel.

So we’re up to ’69. Keep going with your story, it’s fascinating.

So we got to know James. I got to know him more, and a few years later, somehow I ended up sailing across the Atlantic on “Tehini.” It was James, Ruth, and several other girls that were part of the crew at the time, and that’s where it all started. I’ll keep trying to keep it brief.

Tehini Atlantic Crossing

From the beginning I started doing drawing work. [Didn’t] really like the way I was drawing. In fact the Hinemoa plans, which are 23-foot or whatever you’ve got, I drew when I was 19 or something. That was my first set of plans. From then, I’ve gone onwards drawing plans. Of course, more and more, we did a lot of design work together. We design, we work on, we have a sort of brainstorm between us. I would be sketching, and we would be having ideas, and then that evolved into a new design. That’s how it’s gone for years.


In the ’80s, we started building a new boat. We built this 63-foot “Spirit of Gaia,” and we sail that around the world. I still got this boat, and I’m still sailing it. It’s in the Mediterranean at the moment. Over all the years, we’ve done lots of different design projects, and different designs. We’ve sold over 10,000 sets of plans over all those years. There’s hundreds of these boats everywhere.

Now, with social media, there’s a huge following actually. Facebook groups, people talking about Wharram Catamarans quite a lot. Now they are being bought second-hand. There’s old ones, classics, 40-something, even 50-year-old boats that are being bought by people. Then they’re lovingly trying to restoring them back into life.

Oh, that sounds amazing! I think we should probably go back a little bit then, and learn Can you tell us a little bit about where the designs came from, and who James was?

James, back in the ’50s, he read a book called, “The Voyage of the Kaimiloa” about a Frenchman called Eric de Bisschop. Eric de Bisschop, just before the war, had been sailing in the Pacific on a Chinese junk, trying to work. He was very interested in Polynesian migrations, and he was studying the ocean currents and all sorts of things, making lots of notes. Unfortunately, he wrecked his junk in Hawaii, and they were starving on board because they had been held up in the Marshall Islands by the Japanese at the time. It was quite a story.

So he ended up there, and instead of building another junk, he built a double canoe on the beach in Hawaii. Then he sailed his boat together with his male companion, a Frenchman, all the way to France. Through the Pacific, Indian Oceans, went around the Cape of Good Hope, and all the way into the Med to Toulon, which was an incredible voyage. It showed how good a double canoe could sail. It wasn’t totally Polynesian, the hulls were inspired by Polynesian boats, but he put a junk sail on it, and those other junk elements because he was used to them.

Anyway, James read this book in his teens, ran out of the library, was very much inspired by it. Then Thor Heyerdahl came up with his Kon-Tiki voyage, who claimed that the Polynesians must have come from South America because of the ocean currents and the prevailing winds. But having read the Eric de Bisschop book, James was convinced that was not true, and the Eric de Bisschop theory is often coming out of Southeast Asia were correct, which they were of course. So he decided he wanted to go ocean sailing. The easiest for him to build was a double canoe. It’s a very small budget, he built a 23-foot, 6-inch double canoe.

Did the concept of catamaran even really exist at that point?

Not really, no. There had been a Frenchman that built a steel-heavy sort of catamaran and sailed across the Atlantic. It was all a bit of a disaster story. But there were the knowledge of the double canoes of the Pacific, the Polynesian boats. There was a book published called “Canoes of Oceania” by the Bishop Museum in Hawaii, [around] 1938-39, and that was in the library. James studied that quite deeply when he was trying to design his boat, also went to museums studied models.

Anyway, with that boat, they managed to sail from England to Trinidad. While the boat was too small, they suffered from Teredo worms (shipworms). It was built in softwoods, so they built a 40-foot plywood catamaran of “Rongo,” and then sailed that up to New York [in] 1959. From New York to England, that was the first west-to-east crossing by any multihull and that’s what they did. A few years later, they actually did a whole other Atlantic circuit. In fact, that was also still the only catamaran across the Atlantic that way. So that was all in ’61.

Rongo Travels

That’s remarkable!

But they want to sail around the world. Very sadly, James’s other partner, he was living with two German girls/women at the time, she died. It was a terrible shock to them, and it was one crew member missing, that decided not to sail into the Pacific.

He ended up settling down in Wales. At some point, people asked for a design, “can you design me a boat like yours?” That’s where it all took off, in 1965. He started designing different sized boats, and he developed some very good building techniques at that time. Because he wanted always simplicity, he was not in particular experienced or a woodworker, so he always looked for simple methods.

He was quite a bit inspired by an American book actually, “Boat Building in Your Backyard,” which he’d been given a long time ago by an American woman. Because in America, they built a lot of quite simple Dory-style boats and things. James developed a very interesting method, which was building the hulls upside down, and building a plywood backbone, and then slotting bulkheads onto it. That way, people could get the accurate shape of a boat without difficult lofting, or all this leveling and built. You didn’t have to build a heavy building base, and that makes a huge difference. In fact, all our designs are still built in that method. I mean, we’ve evolved it, and made it more sophisticated, but we still use that upside-down backbone and bulkhead methods, and it works extremely well.

Tiki 38 no 182

Let’s talk a little bit about design. In many ways, I would assume James is considered sort of the father of modern catamarans.

He’s certainly considered that, and he is really, because I think in the early days, the majority of ocean-going catamarans were Wharram designs. Now the Lagoons have taken over.

It would be very interesting to have a coffee with you to see what you think of modern catamarans.

You’d be a great admirer of them, I’m afraid!

No! Wharrams are certainly beautiful! In many ways, compared to what’s happened, the Wharram designs have evolved quite slowly. Why is that?

Parallel, but very differently. We’ve always kept with the basic Polynesian principles of having separate hulls, having flexibility in the hull structure, and the general simplicity. The whole philosophy behind it is that you have a a sailing boat, not a motorboat. You can have motors, but the boat should be a good ocean sailing boat. That’s what the basis is behind the design.

But we always keep simple, and we try to avoid a lot of hardware and complications. All our designs now are basically ply-epoxy built, which is an easy way for self builders to build. But the plans are incredibly detailed, so we need to build the right step-by-step through the whole process of how to build it. They don’t have to have technical drawing knowledge, how to read them. It’s all illustrative. I’ve always been good at drawing, so I’m an illustrative artist as well as a technical drawer. Our plans all consist of some measurement drawings, big drawings with measurements which you need. Then a whole book, like a sketchbook of plans, instructions, and they’re all 3D drawings with one, two, three, four, follow the text around it.

I’ve seen a few photos they look like a work of art.

I don’t use a computer to draw. I draw by hand.

How have the designs evolved from the early ones?

With the introduction of epoxy. You see, epoxies came in around about 1980. The Gougeon’s were working on the middle-late ’70s, and we met them at the time. In fact they listened to one of their talks back in ’76, it was a big conference in Toronto. There’s all the multihull designers there, and the Gougeon’s were there. James was quite intrigued by it, but a little bit skeptical when they said it was wood epoxy’s saturation technique. The saturation bits. The question then, how deep does it saturate? In fact it’s more of a coating than a saturation, but that’s beside the point.

If there is insufficent filler mix, just apply more and run the spatula again, until you are happy with the fillet. Use a chisel shaped spatula to remove the excess filler mix. Put it back in the pot and use on the next fillet.

The whole system of using epoxy gave his whole new method by using epoxy fillets. The woodworking skills can be reduced. You don’t have to have absolute accurate jointing and everything, because the epoxy will take care of that. As long as you teach people how to use the epoxy correctly. The whole coating of all the wood and the glassing on the outside makes the boat much more durable than the earlier ones were, because your sealing seals up. It allowed us to to do a lot more sophisticated design work. It was all in plywood, cutting it and fitting together this epoxy.

Hull with all soles and levels fitted.

We started in 1981 with stitching glue boats. We’ve got our whole Tiki range in stitch-and-glue was the small ones. Again, that really made us focus on how to make boat buildings really simple. Our smaller Tikis, the stitch-and-glue ones are really very simple to build and consistent in simplicity. The same technique is used throughout, and not at the end, suddenly gets complicated. It can happen.

Finished cabin fillets.

We didn’t want to make it suddenly complicated when they came to masts and other things. That’s all been part of it and it was very much James was behind it. That’s what he wanted. He wanted it consistently simple techniques and throughout. Then these stickies just evolved bigger and bigger, and every time you go big and you have to work out different ways of doing it. So you get the correct strength, the right balance. That’s what we worked on. I did a lot of work on that kind of thing with working out techniques of how to achieve it easy and simple.

We encountered many Wharram catamarans in harbors around the world, and we saw them in the harbors and they’re always very beautiful to look at, but I always wondered what they were like to sail?

Well, they slipped through the water very easy actually, because we’ve always had slim hulls. All our hulls are at least 11or 12-to-1 beam:length ratio on the water line. Actually, a lot of these modern catamarans say about 8-to-1, they’re much fatter. If you want them to go fast, you’ve got to put a lot of sail on it. Whereas our boats will sail, and it’s very little sail, actually. They’re weak sails. Imagine you’ve got the force forward on our boat we can reduce the sail here to nearly half of it and not lose much speed.

We never aim for some of these really high speeds, but our 63-footer will sail happy at 9-10 knots. The moment you’ve got more wind, it will sail down to half the sail area. It’s a lovely passage-making boat. Because they flex, they go with the waves, and they’re fairly low freeboard, so you’re much more connected to the ocean through the boat. They’re more simple. Some people say they’re spartan, which they may be, but it’s that simplicity that attracts a lot of our builders actually.

Just seeing all this kind of complication and people having everything they have at home on their boats, and we say “I don’t want that, I want to sail, I wanted to be simple, I don’t want things to go wrong.” They choose the Wharram catamarans for that reason.

Tell me a little bit more about the people who choose the cats. I know you talked about that, there’s a real resurgence and interest, and it sounds like it’s the people looking for simplicity.

Yes, definitely. It’s a kind of way of life as well as a type of boat. Of course our boats have a kind of timeless look. We’ve not gone with fashion of boat fashions. Now, fashions every year, you need a new model, like cars. We haven’t gone that way. We stick because the boats are based on a traditional craft from the past. The historic craft, we stayed natural, it was in traditional lines. Sheer lines, overhangs, and things like that, which we feel work.

Our boats still have overhangs of the bows now, all the other cutting ones. Up and down, straight bows, or even retro bows, that’s now the fashion. That’s what you’ve got to have. Whereas, we don’t believe in them.

The other thing of course, we’ve always stuck with V-towers, V cross-section, slide carefully. I still feel that it’s got canoe stern, so even if you load them, you’ll never drag a transom wave behind the boat. They slip really through the water well actually, because they kind of slice the ocean open, there’s a V. Whereas if you’ve got a big round, you kind of push it downwards, and I think that has a different effect on the water.

Of course a V, the lower you go below the water, the slimmer the hull gets. If you have a beam-length ratio of 12-to-1 on the actual sea level water line every time you go down, say six inches, the water line is slimmer, and slimmer, and slimmer. So at the bottom, you’re cutting it with a knife. We don’t need any keels or daggerboards as a result. All the people that sail our boats swear by them, others not.

Right! It’s a matter of sailing them. You’ve talked about new builders who are finding the old boats and redoing them. What kind of people are doing them? Is it a cross-section?

I don’t know, there are all sorts of people that are rebuilding boats. Actually, one interesting thing that’s been happening, there’s been a number of women buying old Wharram catamarans and doing them up. In fact there’s a very large following on Instagram for a woman called Kiana, and her Instagram account is “Women in the Wind.” She got a 50-year old Wharram catamaran and has now sailed it four times across the Atlantic, three of them mostly single-handed, and once with two other women. They report on that a lot and, and they do some beautiful romantic reporting actually. I mean, the boat is simple and it leaks, and it’s rigged with natural spars made from trees, because it was all helped with a friend.

It’s a fascinating Swiss chap called Hans Clark who built a really genuine ethnic double canoe in West Africa. He’s been sailing around the Atlantic now for many years with it. This woman met him and he’s helped her turn this boat into a a new-style boat, very simple. A rig that’s kind of just a rebuilt rig from from older sails, with trees at spars. It’s beautiful, and everything’s lashed. There’s been now a number of women that have been doing that too.

It must be very gratifying to see these 50-year old boats still having such a beautiful life.

It’s also a lifestyle people just love, that basic connection with the ocean. None of this trying to bring your hotel room on the sea. Really connecting with it in a basic way, like people used to sail many years ago.

Then there’s other people. There’s a young Englishman at the moment who’s found a 42-footer by 42 in Holland, which he managed to buy. Somebody built it beautifully actually, but never finished it. It was in the water, it was two hulls, and beams, and some windows that weren’t really fitted on. They’d been lying there for, seven or eight years, nine years, filling with water. It looked a mess. It was filthy, and horrible, and he and I had to look at it over WhatsApp. I said to him, that boat looks well built, buy it. He bought it, for 2000 Euros only, which is the price for a plan.

Everybody was sort of like, “Bob, what’s he buying?” Because then he started cleaning, with all the cleaning, and as the dirt came off, a rather beautiful boat came out from underneath the filth. The bilges had been full of water, but because they were so well sealed with epoxy, which shows again, no rot down there at all. There’s only rough patches because these windows weren’t put in properly, and the hulls were draught. Otherwise, the boat is in very good order.

It sounds like the office is still very active with you there. Is it mainly people getting in touch with you for information about boats, or are people still buying new plans?

Buying plans and building new boats. I’ve got some really good people working in the office here. I’ve got a woman who sends out all the plans. I’ve got a man who does a website, who lives on site here. I’ve got now a lovely young woman called Tori who’s now taking on the Instagram and more social media aspects of it. So it works really well. I’ve actually been going off sailing quite a bit.

Oh! Good for you!

James died 18 months ago about. After, I was offered to sail across the Atlantic with some German friends who’ve got a sister ship to my own, and I took that offer up. That was spring last year. [In] August, sailing the Atlantic. Then in the autumn we got our “Spirit of Gaia” and sailed it from Greece to Sicily. This springtime, I sailed it from Sicily to Ibiza, in the Mediterranean. In September, I want to carry on the voyage to Portugal, which is why I’m aiming for. I want to do an all-woman sail myself, so I’m looking forward to it.


I’ve already got probably two or three, they’re not quite certain yet.

Sounds remarkable! Well, thank you Hanneke, I’ve really enjoyed speaking with you, and it sounds like James has a beautiful legacy. Can you let me know how people can reach you?

First of all, our website is We have a YouTube channel as well, called James Wharram Designs. That can all be found via the website. James and I wrote a book autobiography not so long ago, which was published two years ago, three years ago. That gives our whole life story and everything about boat designs that we built, and how we sailed around the world, etc. There’s a lot of YouTube videos can be found through our website, again. Once you’re in the website, you can read there for hours. It’s not just a selling of designs, it gives all the philosophy, and ideas, and articles about things.

Thank you so much Hanneke, I really appreciate you taking the time today to speak to us at CatamaranSite.

Diane Selkirk

By Diane Selkirk

I love to travel and have spent the past seven years sailing with my family aboard our 40 Woods Meander catamaran - traveling from B.C.'s north coast, to the west coast of the US, Mexico, the South Pacific, Australia, New Zealand, South East Asia, across the Indian Ocean to South Africa and on to St Helena, South America, the Caribbean and Central America.

5 replies on “Interview with Hanneke Boon of Wharram Catamarans”

It’s easy to tell a story and write a book when the major person involved has passed on. Also she doesn’t understand modern engineering or anything. She simply could draw what’s James told her to and now that he’s gone she’s a major part of the story. Lastly this design is nothing that the islanders haven’t been doing for a very long time and James gave them all the credit along with Americans because of our ability to live out our dreams and build boats in our backyards and take chances with sailing or whatever the dream is yet hanneke doesn’t like the Americans being given credit and in older interviews where James is obviously up there in age she’s stopping him and guiding the story she wants told. James Wharram was charging very little for plans unless it was a custom new design and hanneke is detailed to make a nice living from selling James Wharram work with her as the brains behind it all.

Been, from what fantasy did you distill this drivel? What basis do you have to be so mean spirited, when James Wharram frequently called her his partner and collaborator.

I’m a lifelong sailor from a family of software, electrical, mechanical, and aeronautical engineers. I’ve seen nothing in Hanneke Boon’s comments or writing that indicates that she does not understand sailing or the design and construction of multihulls.

I have always loved the aesthetic of these designs and the imagery of the Wharram catalogue. Certainly, Hanneke’s drawings are in large part responsible for the romantic perception of Wharram designs today.

Regarding the comment by “been davis,” who’s to say Wharram was the brains of the operation? Hanneke joined Wharram not long after he started selling plans and has been there for 50 years. Neither of them have any formal education in yacht design and have been known to hire trained naval architects to help with their designs. The Tiki 21, which is probably the most popular Wharram design of all time, says “designed by James Wharram & Hanneke Boon” very clearly on every page of the plans, and that was over 40 years ago. If anything, she seems to be a staunch defender of his legacy.

Been Davis, is obviously lacking in knowledge, Hanneke was maybe more than 50% of Wharram designs over 50 years.
Actually Benn Davis your an uneducated mouthpiece, which nobody appreciates.

Leave a Reply

Your email address will not be published. Required fields are marked *