The Sienna Summary
We did not make the decision to go into fibreglass production lightly but in the end the business head must rule the sailor’s heart so the Sienna 19, our first GRP boat, is ready for production.
I started out with the idea of a bigger faster Stornaway but in the end I based the design on our much admired Secret 20 – in effect she is a slightly smaller Secret with a relatively higher freeboard and a modestly raked stem but has a similar blend of balance, seaworthiness and speed. The brief I set myself was threefold: the Sienna had to address the minor criticisms of the Stornaway 18, she was to be built to exceed all international commercial requirements and a solar electric version was needed.
The criticisms were that the shallower Stornaway keels compromised windward performance, and the freeboard was too low when fully loaded. The first aspect – windward performance, has been progressively improved over the life of the Stornaway and with careful tuning of keel, rudder and rig, any owner can now expect excellent results, given the three-quarter keel and lug rig. In fact over a dozen significant improvements were made to the Stornaway over ten years – the new Sienna incorporates them all and will comfortably out-sail all kinds of similar sized boats. The Sienna’s deeper keel is about as far as I can go and yet still allow for easy launching and beaching. As to freeboard, it’s a tough one to keep her looking lithe and lean yet still keep the spray off grandma’s new outfit. We think we have succeeded.
Drawing on all those years of experience and fine tuning with two of our most successful boats, Sienna is the logical evolutionary step towards our perennial goal of boating perfection. Quality, both of build and performance as well as practicality are the important issues – the new boat will be judged a failure if it is awkward or irritating to use so we set out to engineer every ergonomic aspect so that she will be a pleasure to use over years of hard service. Performance will be better than Stornaway, principally to windward where a slightly deeper keel and larger rudder combined with a well tuned third generation lugsail yawl rig will all but eliminate Stornaway’s only real Achilles’ heel. Off wind a lighter hull, more ballast, increased waterline, finer entry and flatter sections will undoubtedly add speed. For auxiliary power we specified an electric inboard or outboard – not only kind to the environment but also powerful and easy to use.
In the early days of the 20th century most small motor boats followed on from sailing hulls with their proven abilities honed over thousands of years. We’re doing the same with our motor Sienna except that our hulls are built from super strong, super light, foam-cored fibreglass and underwater they look more like 21st century racers than 19th century fishing boats. The ballasted keel is replaced by a skeg but the easily driven sailing hull is now powered by Torqeedo electric outboards. The high capacity batteries, charged by solar voltaic collectors on the canopy, may also be charged overnight and with a back-up generator onboard, the Sienna motor boat is ideal for private or commercial use. The low running costs will be appreciated and the installation of battery banks low down in the bilges creates excellent extra stability within the tough lightweight hull making for a safer, easily driven and more comfortable boat. The electric Sienna will cruise for eight to twelve hours on a full charge.
Internal layouts were decided on pretty early, the brief called for eight passengers to be accommodated in the sailing version so we had to think carefully about this. We opted for the Stornaway Camper layout as being the most practical and cost effective solution, solving a number of “challenges.” Six can easily be accommodated in the self-draining cockpit with two (or more) down in the lower level using the bunks as seats. A canvas cuddy can quickly be raised for weather protection or for the use of the porta-potti which slides out from under the cockpit sole. The two full-sized bunks are fitted for comfortable overnighting with awning/boom tent extending aft for two more to sleep in the cockpit. Extra toddlers can be wedged between adults. The electric motor version was easier – most of the hull is open for seating up to ten passengers under a near full-length canopy.
So that’s construction, performance, practicality, seaworthiness and power covered – so what else?
Well aesthetics are pretty obviously one of my obsessions – anyone who agonises about raising a sheerline a few millimeters is clearly a man with a mission so the boat had to look good in and out of the water but ultimately you’re the judge, not me. A number of tricky design solutions have as much to do with appearance as with practicality, among them a sink sliding out from under the cockpit seats, a grab rail which doubles as a canvas cuddy support, and an efficient means of stowing the electric outboard to name but three.
Safety is clearly a vital consideration and all of the things that make Sienna a comfortable boat also make her a safe boat. Good form stability and a high ballast ratio means that the hull resists heeling, a boomless rig is safe for children and the less agile, and various specifications required for the commercial versions will also benefit private buyers.
So that’s settled then – a beautiful, fast yet utterly practical trailer sailer or an excellent electric passenger launch – both equipped to sail the 21st century’s troubled waters.
Derek Ellard
Designer
2009