The Most Interesting Ronstan Customer in the World Part 2: Designing a Racing Proa

by Tom Stuchbery

For this issue of Tell Tales I wanted to write an article that inspired yachties from a full spectrum of the sport. As a lifelong sailing addict, I thoroughly enjoy the conversations I have with customers on a day-to-day basis, with work often feeling like a brilliant never-ending game where sailing questions of varying complexity are constantly coming through. One customer might be seeking a replacement block for their Cavalier 37, the next might be looking to reinvent racing multihulls entirely. This article focuses on a customer of the second category.

I vividly recall my first encounter with Matt Tucker. It was April 2020, COVID was starting to spread throughout the world, and I was making the most of temporarily inheriting the office of a senior colleague thanks to social distancing measures. We received an email from a customer in Tasmania building an experimental racing proa with a 360° rotating rig. I knew I must find out more, so I immediately called Matt Tucker.

I soon found out that not only was Matt building a very interesting racing proa but he had also grown up on a home-built 48 foot Herreshoff Ketch named New Zealand Maid along with his 4 brothers and in 2006 had sailed from Hobart to Commonwealth Bay, Antarctica, with his brother Ben and father John on the 34 footer Snow Petrel. The best part about this was that he made a fantastic three-part Documentary about the voyage, which is available on YouTube, and I somehow hadn’t seen it yet!

Given the scope of topics and details I wanted to know, I found it hard to combine all the questions I had about these topics into one digestible article, so I thought I would simply list them all below for the reader to tackle one at a time.

Our readers may not be familiar with the proa concept, basically a proa is an ancient catamaran favored by Pacific islanders with a long leeward hull and a short windward hull. The rig is traditionally on the leeward hull. So why did you decide to build a racing proa? What are you hoping to gain compared to a traditional catamaran and what type of racing is it designed to do?

Okay, so, what initially drew me to the proa was it was out of the ordinary and unusual, which my character is always drawn too. The thing I always say to people is there’s three types of multi hull, the Cat, Tri and Proa. All 3 were initially modernized at the same time. If you look back at the 60s, 70s and early 80’s, they would all race against each other and the proa would hold their own. Then people got carried away and started making high risk proas that capsized a lot, so then they got banned. The rules still ban proas to this day. So, I just thought, what a terrible reason for there to be no racing proas! And then I started to look at the calculations of sail area and power to weight ratios of cats, tris and proas. It makes sense to me that the proa has the potential to be as fast or faster than any other multihull. So that’s what I set out to do, test the theory. I hold no attachment to the idea that it will be better or faster, I just want to test it so that I can be convinced either way.

In terms of the racing that it is geared towards, I see proas as potentially excelling in shorthanded offshore racing. So, the idea with this one is to test ideas and configurations and then scale it up to something offshore capable.

Talk us through the specifications of the boat and how you constructed it? What materials have been used?

The only standard part is the rig,the construction was basically just foam, fiberglass and plywood, with a bit of carbon as those materials were suitable for the different jobs. Nothing overly high tech. The windward beams are aluminum tube and the leeward beams are carbon fiber.

So the rig looks to be off an F18 beach cat, is that correct? There is a 32mm Ronstan I-Beam track, which we curved into two semicircles, to form a complete circular track. This has cars on it which takes the stays and allows the whole rig to spin around in order to be able to “shunt” and sail in both directions. Within this, you look to have a rotating wing mast, with the angle being set relative to the boom, like some beach cats. Can you explain how you operate the rig whilst sailing? There must be a way to lock the rig to a particular angle?

The mast is off a Nacra. So, the easiest way to think about is the whole rig is sheeted like you would normally sheet your mainsail. Everything moves all together, so the stays, forestay and mainsheet all move equally. You sheet it by moving it around in relation to the breeze. So, what is normally considered the mainsheet, is just a vang, and then the rotation changes the angle of attack. To the average sailor it’s like adjusting the traveller on your mainsheet, except the whole rig is moving with it. The other element that people miss is that I don’t need to sheet the jib. There is a small self-tacker on the jib, so basically when you “sheet on” the mainsail comes to windward and the tack of the jib goes to leeward, which is the same as pulling the jib sheet on a traditional boat. Basically the setup is complex, but the actual sailing of it is super simple.

Many of our readers will be familiar with the nuances of setting up catamaran rudders, and how changing the rudder toe-in 5mm can totally alter the performance of the boat. Can you explain how the twin rudders work, and how you keep them at the correct angle relative to each other? Are the foils symmetrical, or do they spin around when you shunt?

The foils spin around when I shunt, which is a performance decision. In terms of the angles and effecting that whole thing, I’m still experimenting with that. The advantage I’ve got is that I can adjust them both in relation to each other, so they can be adjusted independently of each other using long tiller extensions for experimenting. I then lock the forward rudder, which becomes the centerboard, with an eye-bolt and a big screw, with a bit of bungee holding it there. The idea is that I’ll have multiple points for the eye-bolt to go into, depending on the angle of attack for the forward rudder. I haven’t sailed it enough yet, but I expect that there will be multiple settings depending on breeze.

How does it go with fore/aft trim? Does it feel like it could nose dive going downwind, or is the rig height relative to hull length enough to keep it under control?

Unfortunately I haven’t sailed it enough to get a feel for it, I built a lot of rocker into the main hull to try and get some lift into the main hull and some suction into the stern, I’m hoping that will be enough. The other point there is that the length of the hull compared to the height of the rig on a well-designed proa is longer than an equivalent catamaran. If you think about the overall weight of the proa, it’s quite light, so you use that extra weight advantage to add extra length to the main hull. That gives you a longer, skinnier hull, which is what drew me to this project. You don’t need to build two or three of the same hulls to get the same effect, so the weight saving is massive.

Most importantly, how does it feel to sail?

It feels bloody good to be honest. There were two things I wanted to try out. The balance is the hardest thing to get right on a proa. Like being able to shunt without getting stuck in irons. It’s something that every proa person has trouble with. That’s part of the reason the rudders are way out to leeward, to offset the ama to windward (and maybe have foils one day). In terms of the control and the sailing feel of the boat, it feels exactly as I wanted. Super balanced, easily driven. I’ve ticked the boxes there, now I just need to refine it.

The other part of the sailing side is that you don’t need to move from your sailing position, you don’t need to move from where you’re sitting, which is quite nice. And you’ve got a really good view of the rig compared to a monohull where you’re sitting under it. You’re really removed from it and you have a really good view of what’s going on with the boat.

Check out Matt’s Instagram to follow along with the latest on Matt’s racing proa. Matt has also recently launched a business building classic boats for the modern world using high performance, low environmental impact composites. Please see http://evergreenboats.com.au/ for details.

Ronstan thanks Matt for his time and assistance with this article, particularly when phone challenges made it hard!