Copyright 2017 - Woods Designs, Foss Quay, Millbrook, Torpoint, Cornwall, PL10 1EN, UK
  • home built Flica 37

  • plywood Romany 34

  • lightweight 14ft Zeta mainhull

  • Strike 15 trimaran at speed

  • 28ft Skoota in British Columbia

  • 10ft 2 sheet ply Duo dinghy

  • 24ft Strider sailing fast

  • 36ft Mirage open deck catamaran

This article is based on a talk I gave at the 2013 Port Townsend Wooden Boat Festival, which is in the USA, so it was given to an American audience. I began by talking briefly about my career and my introduction to sailing in the Pacific North West, which you can read elsewhere on this site, so I won't repeat it here, and then I said:

"So that's a brief introduction about me, I'll talk more tomorrow about my multihull sailing and design experiences.

Right now I am going to talk about what might make an ideal PNW cruiser. In the last 7 years my wife and I have owned two sailing trimarans, a sailing catamaran and 2 powercats in the PNW. I've also sailed monohulls around here, not just the Downeast38, but several others, including a Thunderbird in the Shipwrights regatta held here in February, and most recently I raced a wooden 6m, built in 1938, during the Vancouver wooden boatshow. So I’ve been able to sail all sorts of boats in the PNW

We have a waterfront summer house on Saturna Island, which is one of the Canadian Gulf Islands. So even when we are not cruising we spend a lot of time looking out over the Strait of Georgia.

I think everyone knows that winds are light here for most of the summer, so much so that for weeks at a time anything over even 10 knots is a rare event.

Unlike, say, San Francisco, where one really only sails in the Bay, here in the PNW there are many places to cruise to, even if you just daysail. For you can go hundreds of miles, anchoring each night, yet staying in sheltered water the whole time. After all, the most popular cruising boats round here are actually kayaks, with their paddlers camping on beaches at night.

A kayak is very limited to wind and seastate, over 15 knots and they go into survival mode. Which really proves how benign the local weather conditions are. You don't see kayaks in the UK, it's just too rough and windy.

To get to more distant cruising grounds even multihull sailors like ourselves spend a lot of the time motoring. We got frustrated drifting around until say 4pm when, 10 miles short of our anchorage, we'd start the engine and motor in for the night.

For unlike the UK and the east coast you cannot sensibly sail at night, there are just too many dead heads and logs. Having said that one of my most memorable sails was in the Swiftsure race, sailing Bad Kitty at 22 knots through Race Rocks at 1am on a pitch black night.

Again, if we were cruising in the UK, or on the east coast of the US, we could have a trailable boat and drive to our favorite cruising area. But up here, once you're north of Lund there are no coastal roads, period, so you have to get further north in your own boat.

Even if you are live aboard cruisers you still have limited time, because the summer season is short and few people want to leave their boat in Alaska for the winter. Unfortunately the Canadians have now made it difficult to leave your boat in Canada without paying an 8% sales tax. So you have to allow time to come home again.

So on a long trip, and with limited time, you need to make fast passages, so you can get to your destination quickly and then relax and enjoy yourself. And unfortunately round here you cannot do that under sail. After a lot of soul searching, for after all I've been a keen sailor for 50 years, we eventually decided the best thing to do was to have a fast daysailing boat for the days when there is wind and we wanted fun on the water, and at the same time to have a powerboat for cruising further afield.

OK I know you can motor a sailboat. And it is often fuel efficient to do so when compared to a powerboat. Even so I cannot see why someone would be motoring their sailboat downwind in 15 knots of wind, especially early in the day, as so many people seem to do. I mean if they don't sail in ideal conditions then when do they? Maybe it's simply that having a sailboat was a romantic dream and it's just too much effort to sail one efficiently. Or maybe they find they are more comfortable driving a boat like you do a car, rather than actually learn how to sail. I don't know, any ideas? but wouldn't they be better off with a powerboat in the first place?

Before I describe the boat we now have, and the reasons for choosing it, I want to digress for a moment and talk about yacht design in general.

Ocean going boats have always done two things. Carry lots of people or carry a heavy cargo. Much of boat's development happened in Europe where generally it is easier to move people by land, not sea. So most boats there were designed to carry cargo. Thus they were big and heavy and relatively slow. Yachts developed from these boats and so also tended to be heavy and slow as that was what people expected from a boat.

The place where it is impossible to move people by land is the Pacific ocean, and it was there that multihulls were developed, as they are ideal people movers with a big level deck space for living onboard and easy beaching anywhere.

People are a light cargo and want to get to their destination quickly, which is still as true today as it was 2000 years ago.

You all know the phrase “it's not rocket science” meaning it's not the ultimate in technology and design. Well I say “rocket science is not rocket science, but yacht design is”

I went to the Kennedy space centre a few years ago and got talking to one of the Saturn rocket designers.

I asked him what he would change if going to the moon today. He said, “only the computer”. The rest was basically just a big fuel tank, while I was surprised at how small and simple the engines were. I believe the Russians still use the same basic rocket that Gagarin used. The space shuttles first flew over 30 years ago, so were obviously designed much earlier. The supersonic Concorde aircraft was designed in the late 1950's

Now think of the changes made to yachts, and especially to multihulls since 1968

It is easy to design something static, like a bridge or a building. It doesn't have to move, or even float. So you can put a steeple in a corner of a church and not worry about it falling over.

Once in space a space ship has no loads, no gravity and only one atmosphere between the interior and outer space. Even a static houseboat is harder to design – it has to float level for a start.

Harder still to design are moving things, like a car or plane. They not only have to keep their shape and support a load, just like a static building does, but they also have to move efficiently.

Hardest of all are what I call “interface vehicles” like boats, that work in two mediums at the same time. Air and water in our case. Planes don't usually fall out of the sky, or break when taxiing on the ground. They have incidents when landing and taking off – just when they become an interface vehicle. Space craft have their problems on re-entry when they reach the interface of the atmosphere.

Everything in design is interconnected. It's what we call the design spiral.

At it's simplest - suppose we want a boat to go faster. We put in a bigger engine. But that's heavier, so the hull has to be bigger, so it has more drag, so goes slower, so we have to put in an even bigger engine. That is spiralling up and is the easy option.

An alternative is to make the boat lighter. Then we can use a smaller engine, so the loads reduce, so we can have thinner scantlings, so we can have a yet smaller engine. That is spiralling down and is usually the route I prefer

Although it is easy to find a solution to a problem, it's much harder to come up with a simple one. Harder still to design something that can actually be built. Hardest of all is to design something that can be built in wood

It's best to design the whole boat in your head first, only later do you draw it. Even then you can expect several false starts.

The smaller the boat the more you have to compromise your ideas. That's mainly because people don't get shorter when they go on a smaller boat. So, for example, freeboard is always proportionately higher. Furthermore the essentials for living on board weigh pretty much the same for a small boat as a big one.

Clearly when sailing at sea you always need a minimum freeboard for safety and comfort on board. The bottom line is that the bigger the boat the better it looks. Not only that but bigger boats perform relatively better. So it is really hard to make a good looking, fast, small boat. Science and the human anatomy are against you.

Usually professionals draw the lines plan last. For you cannot finalise that until you know, for example, how big the engines must be to go at the required speed. And thus how much space they take up and where the centre of gravity will be.

A good hull shape isn't just a matter of having the right centre of gravity and displacement. It also has to allow the boat to move efficiently through the water. After all, and as an extreme example, a boat might float level and on its marks at rest, but may do 60 knots going forwards and 6 knots backwards. So knowing which end of a boat is which is important!

Before developing my Skoota range of power catamarans I studied the available data on pontoon boats.

I found that a typical 20ft pontoon boat weighs about 1500lbs, so is similar to a Skoota 20, yet it needs a 50hp outboard to motor at 16 knots. Whereas the Skoota goes that speed with a 25hp. Or put it another way, the Skoota hull has nearly half the resistance of a similar sized pontoon boat. Proving that proper hull design DOES matter.

And in some ways having an efficient hull is more important on a powerboat than even a racing sailboat. That is obviously because a powerboat hull with higher resistance uses more fuel, whereas the wind is free.

So who thinks fuel is expensive here? Well for comparison in the UK gas costs USD 9 a gal, in Canada it is USD 6.4 a gal. Even in the Philippines it is over USD4 a gal and that is in a country where the average wage is under USD300 a month. Right now gas is 3.20 a gal in Seattle. So you shouldn't be surprised that boats have smaller engines in other countries, and that huge sectors of the US boating market, like sports fishermen for example, just don't exist anywhere else and will die out here once US fuel prices match the rest of the world.

And while on the subject of fuel. To get to Alaska you only need a maximum range of 250 miles. Less than you need in the lower Mississippi if you are doing a Great Loop cruise. Mind you in many places round here you can buy fuel, but there's no water. Saturna and Galiano are two Gulf islands with no dockside water.

OK, back on topic:

Monohull sailboats are very different to powerboats. They roll in both wind and waves, they heel over, have a deep draft, a small cockpit and limited accommodation, and generally have no view out when down below. So it is a big change to go from a sailing monohull to any powerboat, whereas a sailing catamaran is similar to a power boat in many ways. Both offer level sailing, good accommodation with all round visibility and no deep keel. So maybe that's why it has been easier for us to make a transition from a sailing catamaran to a powerboat.

So given that we wanted a powerboat what sort should it be? There are 4 basic choices: displacement, planing, semi displacement and multihull - and I think you know which I'm going to suggest.

But before I do I'll talk about the options.

Displacement boats are slow and heavy, but as a result generally have a seakindly motion. They are limited to their “hull speed” which roughly is proportional to 1.34 times the square root of the WL length. So it's difficult to go over 8 knots if the boat is under 40ft.

Thus most displacement powerboats cruise around 7knots, just like a motoring sailboat does. They are usually sold as rugged “go anywhere” vessels, and, because of their bulky hull shape, fuel consumption can be high if motored fast. However many people say they look like a proper yacht and many displacement boats are sold purely on that classic styling look

Planing hulls are typically at least twice the speed of a displacement hull of the same length, slower than that and they aren't fully planing.

They are very inefficient at slow speeds due to the transom drag. And are also less seaworthy, because in bad weather and big waves

when they are forced to slow down, they trim down by the bow and so the risk of nosediving is considerable. At best they are then wet and uncomfortable. Even in flat water the hull slams when planing, so it is uncomfortable and noisy on board underway. The engines have to be large and they use a lot of fuel, so much of the interior is taken up by machinery and tanks. That reduces living space and also means engine noise, smell and vibration increase.

A semi displacement boat

might be a good compromise, or the worst of both worlds. In part it depends on the cruising speed you chose. One definite advantage is that one can go faster when needed - to outrun bad weather, catch a tidal gate or even cut across the bow of a ship, which a displacement hull can never do. However it is never as efficient as the other types, so fuel consumption is higher than for a displacement boat. It will have more room than a planing boat as the bow section will be fuller and probably has a smaller engine space. Another drawback of the semi-displacement is poor seakeeping in a following sea, while steering can also be tricky unless you can outrun the waves. But even so, it's way better than a planing boat that has slowed down.

Power catamarans

offer many significant advantages over monohull power boats. In general they offer low wake and much improved fuel economy compared to other powerboats. They are comfortable under way with no slamming or broaching in waves and have excellent handling in a seaway, They use two small engines not one big one. That's clearly much safer and more manouverable. You can turn on the spot without using the rudders for example. You can run just on one engine when cruising at low speed, or run one for battery charging, which is better for the engine life. They do not roll when fishing or at anchor and are easy and safe to beach. If you don't roll at anchor and have a fuel efficient boat you visit marinas less often and can spend the money saved on more fuel so you can cruise further.

They can maintain high speeds in rough conditions, and have superb directional stability. They are safer, due to their high stability, fully buoyant hulls and self draining cockpit. They do not heel when cornering, nor trim excessively at speed, so you can always see what's ahead They have more deck and interior space for a given length, not just because of their wide beam, but also because they have an essentially rectangular living space. Thus they do not have to be as big as a monohull to give the same interior room, performance and safety. Furthermore, docking is easy on a catamaran as its sides are essentially parallel, while anchoring is also easier on it's big wide foredeck.

And that's one reason why I don't think a power trimaran is a good idea is, because it is so hard to dock or even to board when alongside.

However most power catamarans available today are planing boats, with all the disadvantages that the type implies.

Furthermore they tend to have a narrow, 8ft 6in, maybe up to 10ft beam, so they can be trailed, so that many of the advantages of the catamaran form are wasted. In part the choice of design boils down to how fast do you really want to go and why? You aren't on a cruise ship with deadlines, nor towing waterskiers. It seems that few boats cruise at more than 12 knots, however fast they potentially are – I know that, because we overtake most cruisers when going at our normal 11 knot cruising speed. So few cruisers really benefit from having a planing boat.

Regardless of hull type, one of the big differences between a sailboat and a powerboat is you helm a sailboat and drive a powerboat. You don't need to look at sails and don't need to feel for weatherhelm. So you can steer from anywhere, inside or on the coachroof, or both. However twin steering is not only more complicated, but also takes up more room, both inside and out. For remember you have to include a passageway to the helm seat. So basically on a small boat it's not worth it – as I said, everything is a compromise

A flybridge has more motion when at sea and needs protection so you end up with a third story, with lots of added weight and windage in the wrong place. When it's not very clear outside, interior reflections will interfere with visibility from an enclosed wheelhouse. As will steam from cooking. Maybe it's because I'm a sailor, but I prefer the conventional behind the aft bulkhead at the front of the cockpit helm position. That position also means I can see the sterns, which is often really important when docking

Now I want to talk briefly about stability There are three basic ways to lose stability, the first is by wind, which obviously mainly affects sailing boats, but also some high freeboard powerboats in very high winds. The second is by being rolled over in a big wave and the third is after being swamped, usually because your cockpit is too big and when full of water the stern goes underwater and the boat sinks.

The only sort of boat that can self-right from a knockdown is the monohull keelboat, but even then it may still need rescuing, in part because hatches may be open and the boat floods. I'll show you a video tomorrow of what I mean

All other boats throughout history can capsize. A typical fishing boat or even warship will capsize at about 40deg of heel, so a trawler yacht will obviously be much the same. We’ve been on a US warship in bad weather and were told - “we’re staying hove to, it’s too dangerous to continue into it, and yes even we stop fighting in a storm - but then so does the other side“. A high freeboard boat with a flybridge probably capsizes at an even lower angle.

Although a low c of g is very important for stability in a sailing monohull it is less so on other boats as it only has a major effect at high heel angles. A high cofg still increases pitching and rolling though

If you don't have a deep ballasted keel then you have to rely on what we call “form stability”, which is the shape of the boat. At its simplest a boat is considered stable in waves until the wave height exceeds the beam of the boat, so the wider the boat the safer it is. And if you heave to and stop you are generally safer than if you keep moving. Unfortunately, wave resistance is proportional to the cube of the wl beam, so narrow hulls are faster, but less stable

One of the worlds leading yacht research centres is Southampton University's Wolfson unit. Some years ago they performed model tests of various boat in waves. I've seen the videos they made, which were more realistic than even the Perfect Storm movie. However they are not public domain.

In the Wolfson tests they found it very easy to capsize a monohull powerboat, but try as hard as they could they never capsized the power catamaran.

Ok that's the basic choices, now we need to refine it

As I've just said, design is a spiral, but one has to start somewhere. Lets start with size.

So how big a boat should the ideal PNW cruiser be? I always say get the smallest boat you need, not the biggest you want. Smaller boats are more fun, and easier to handle. Obviously they are also cheaper to buy and maintain. For remember running costs are usually about 10% of the purchase price. I never go for styling for the sake of it, I chose the boat that best meets my needs regardless of looks or price. And please, don't think “we'd better buy a big boat, just in case the grandchildren want to come” Instead, get one you can handle easily with just your normal crew. You'll use it more and it won't be such a stressful experience.

Famous local designer Bill Garden has said that the ideal sized PNW coastal cruiser for a couple with occasional guests is 32 feet. Which is a good match for the “drinks for 6, meal for 4, sleeps 2” concept.

You live in a house, not a hotel, so when cruising for longer periods you’ll want a comfortable home, not a hotel room. That’s why buying a boat designed for chartering doesn't make much sense. Most cruisers don’t want lots of bunks and ensuite showers. Instead, one good double bunk is enough, although maybe a spare for friends or family is useful. More important are a big galley and a good heads compartment.

Absolutely essential is a comfortable saloon with an all round view. After all, when on land we don’t choose to live in a basement, the expensive apartments are always the penthouse suites. So cruisers, who spend much of their time at anchor, should be able to enjoy the view from inside, not just from the cockpit. Of course being able to stay inside, yet still be on watch, makes passage-making safer and that much more enjoyable. Especially round here with all the floating logs and weed to avoid.

My first power catamaran was the Skoota 20 which we built in Canada and used for a couple of seasons.

Our longest trip was to the Princess Louisa inlet, but since the cabin was only 5ft long it wasn't that comfortable for long cruises, for it was really built as a test bed for my ideas.

It worked well, so I later drew 24, 28 and 36ft versions. The two small boats fold and are trailable, the Skoota 28 is transportable, as it bolts together, and is the one I have on show here.

The Skoota 36 is a live aboard cruiser, there's a wooden one being built in Vancouver for an experienced cruising couple. They just came back from a Pacific cruise, and, like us, have chosen a powercat over a sailing boat as their ideal PNW cruiser

My Skootas use semi displacement, non-planing, asymmetric hulls.

The hulls are finer than those used on a sailing boat, because power boats always have power available to get over the hump speed, so wetted surface friction drag is less of an issue, as that's really only relevant to slower speeds, well below the normal cruising speed for a powerboat

Tank testing I've done has shown that there is significant extra drag caused by wave interactions between the hulls, it's up to 20% at certain speeds, if the hulls are close together. That's one very good reason why I don't like the narrow powercats you see around. My Skoota 20 and 24 are 12ft wide but fold for trailering.

The Skoota 28 has widely spaced hulls, yet will still fit in a standard 14ft slip. Put simply, the hull asymmetry helps fool the water into thinking the hull spacing is wider than it really is.

In the last 10 years we have owned sailing catamarans from 25 – 38ft so we have a good idea of the size of boat that suits us best. Basically we know that 38ft is too big for us - the 38fter we sailed had 800sqft of living space. Bigger than our PT condo. Lots of boat to maintain and clean, even when at anchor, never mind the extra effort involved in sailing it

We had thought about building my Skoota 36ft powercat design, but after looking at similar sized monohull powerboats we realised that even that would be bigger than we needed, and certainly the running costs would be be higher. It might be different though, if we were living on board full time.

So we decided to have a Skoota 28 professionally built in wood. And that's something you should consider doing as well. Buying a one-off wood boat direct from the builder can actually work out cheaper than buying a production grp boat as you don't pay for the mould costs, nor for sales commissions.

But the big plus is you get the boat you want, not what the boatyard wants you to have. We were very lucky with our builder, Josh Turner. A bit of a gamble using an unknown boatbuilder, but we were very pleased with his quality and speed of work.

I don't like maintaining engines so I prefer outboards. They are lightweight, reliable, self contained and keep the engine noise and smell out of the accommodation. The new fuel injected ones are as efficient as diesels and you can take them to a mechanic for service or repair, not the other way round. You need fewer seacocks and hull fittings, so there is less chance of leaks. In fact on our boat we have no skin fittings at all, for not only do we have outboards but we also have a composting toilet made by C-head, and an excellent buy. We don't even have any bilges, so have no need for a bilgepump. Our insurers think we have a safe boat as they know the most common claims are for engine failure and hull leaks, or even sinking.

I won't tell you any more about the layout of the boat as you can go see it, and in fact you might already have seen it online in Wooden Boat magazine as it was last weeks “Boat of the Week”. But I will show you this video

 

It was taken shortly after launching. Since then we have adjusted the outboards so the boat trims more level. And we've fitted the cockpit seats and bimini and raised the helm seat on a pedestal. Although the top speed is around 16 knots with our twin 20 hp outboards, we usually cruise between 10 and 12

And you might find our fuel consumption figures interesting. A couple of weeks ago we took Skoota to the Vancouver wooden boat show. It was a 38 mile motor. We did it in 3 ¾ hours and used less than 5 gals of gas. That 7 mpg is typical of our cruising this year

We have yet to connect our main fuel tanks so are still using the 3 gal tanks than came with the engine. So I am not giving figures based on saying the tank was half full, now its ¼ full. Rather on how much is left after refilling the 3 gal tanks with a 5 gal one, so it's an accurate figure

Well that's it really. If any of you want a trial trip in our Skoota, well we will be living on board and cruising round here until mid October when we fly to Europe, so any time before then. The Skoota will be left in a local marina for the winter ready for our next trip north

Thank you"