I have resisted designing a small bridgedeck cabin catamaran until now because I was brought up sailing in the generally rough and windy English Channel and so have always designed boats that would suit those conditions. However, as I travelled the world I began to realise that many areas have much more benign conditions than we do in the UK, particularly in the USA and Australia. Both places where people may live a long way from the sea and sailing on lakes is their only option.
Which is probably why the small trailable bridgedeck cabined catamarans are popular in those areas.
Saylon is my version of the concept. It will appeal to those who want to gently cruise for the weekend with a young family (or maybe with grandchildren!) in sheltered sailing waters. It is not intended as an offshore boat, nor for those who want to race. Please check out my other trailable designs if that is what you want to do.
It is a very small boat - some beachcats are longer - so at most it is really only suitable for two adults and two small children. Most small boats trim by the stern when the crew sit in the cockpit. Furthermore, with a single forward cabin the parents get no privacy.
So the major difference between Saylon and other similar boats is that there is a centre cockpit and an aft double cabin. That helps keep the weight out of the ends, it also makes sail handling easy and separates the living and sleeping areas.
I call Saylon a "motorsailer" because it will not be as fast a boat as my Acorn or Janus designs, for example. The hulls are simply too fat and too close together. The rig is small because the narrow beam means that stability is limited. That's also the main reason why I call it a "Sheltered Water" only boat (Category D under Europe's RCD).
The rig can come from a beach cat eg Hobie 16. The mast is stepped on the cockpit floor so that it is easy to raise. It would be a real struggle stepping the mast from the cabin top. Hoisting the mainsail and reefing can be done safely from the front of the cockpit. With a furling jib there is no need to go on the foredeck when underway.
The sails are small enough that no winches are required, the jib has a 2:1 purchase. The mainsail has a good downhaul and a "gnav" (an upside down kicking strap as seen on many racing dinghies) to control sail twist, yet not intrude into the cockpit. So the sails can still be set efficiently.
The steering is "monohull friendly" with a central tiller and cockpit seats as on a monohull. However, extending "wings" can be used for more crew righting moment for keener crews.
Saylon may be a small boat, but it's huge compared to a 20ft monohull. In part that's because it is basically a rectangular shape, there's no "pointy bit" at the front! But also because the whole deck is usable space, on a monohull you're generally restricted to the windward side.
The whole deck area is maximised, there is no forward trampoline, and the bridgedeck is taken as far aft as possible, leaving room for the rudders and outboard. Transom steps are built into each hull. Watertight compartments are built in for safety in case of collision or damage when grounding, but there is still plenty of storage space both above and below deck.
The Saylon is small and light enough to be towed behind a small family car on a simple flat bed trailer. And, with no assembly required - apart from raising mast - you'll spend no longer at the slipway than you would launching a monohull.
One unusual feature of the Saylon is also seen on my Wizard and Sango designs - the "pop-bottom". "Pop tops" are common on camper-vans and small boats alike, indeed one is used on the Saylon. The pop-bottom is a similar concept, but in reverse.
The forward part of the bridgedeck is lowered when at rest, giving extra sitting space and standing headroom, and raised when underway. A waterproof "bag" surrounding the pop-bottom keeps you dry! That gives Saylon nearly 1sqm (10sqft) of standing area in the saloon. A table can fold against the aft bulkhead to port, but probably a better solution wold be a cheap picnic table, as that could also be used in the cockpit.
The hull shape is based on a combination of my very successful Strike trimarans and my Skoota designs. It is basically a flat bottomed dory hull but V'eed near the bow to reduce slamming. The topside chine, as used on the Skootas, increases space below without changing the overall beam, which obviously is limited by the trailerability requirements.
The side decks allow easy boarding and walking forward when coming alongside (remember there is no need to go forward when sailing as everything is controlled from the cockpit.)
It is a flat panel ply/epoxy boat that is very easy to build single-handed in a regular garage. Allow 500 building hours ready to paint.
Boat weights are notoriously difficult to predict, the 680kg I give is probably pessimistic, but is based on known weights of similar boats ready to sail, ex crew. For example, our slightly longer Wizard was weighed at 700kgs ready to race. Other designers may well give the weight of a bare shell, so be careful when comparing designs!
You can see more details in the provisional study plan HERE. Digital download plan price will be GBP180 (USD280) for the first 5 sets of plans sold.
This article, which is based on the talk I gave at the "Sail Havasu" pocket cruisers meeting in Arizona in 2012, should help you decide whether a small multihull is the right boat for you.
Richard's plans are available in the Duckworks store.