In-Depth, Aluminum Boat Design & Selection, Part I
By Guest Writer, Colin Speedie
Index
Part I
Introduction
Turning the Dream Into Reality
Choosing A Suitable Boat, New Versus Old
A Boat Built to Travel
Making the Most of Aluminum
Part II
Self-Defence in Harbour
A Practical Interior at Sea or in Harbour
Limits to Complexity
Are Spade Rudders Suitable for Ocean
Crossings?
A Practical Cruising Rig
Part III
The "S" Word—Stability
Anchoring in the Modern World
Self-Sufficiency in Power
The "C" Word—Corrosion
Electrical
Systems and Aluminum Boats
What Has Worked So Far—Domestically
Introduction (by John Harries)
Some time ago, we got a most thoughtful and clearly written e-mail about anchoring from a very experienced English cruising sailor named Colin Speedie. Since then we have discussed a variety of issues with Colin via e-mail and have always learned from him. We have posted his original communication here.
Colin and his partner Louise Johnson have just completed building their dream cruising boat. They very kindly agreed to share the process with us and our readers in a series of posts. In addition, since they are from England and had their new boat built in France, they bring a European prospective to our site.
Their choice of boat, while as
different from Morgan’s Cloud as you could possibly imagine, is
a boat that has long interested us. I won’t give any more away.
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Turning the Dream Into Reality
Ever since I was a small child I have had a fascination with building things, or making them better—boats, cars and motorcycles have all come and gone in this manner. Some started as good basic raw material, others as well formed objects that simply needed fine tuning and affection.
And like many of us who love to sail, my ultimate dream has been to build a boat capable of going just about anywhere imagination can take me. And to my great good fortune, for the last few years I have had a partner in life (and sail) who shares that dream—so now there’s no excuse for either of us not to dream by day. So now, children grown, businesses sold, and the deposit paid, our coin is down the well.
So we now hope to distil a lifetime of sailing experience into creating a boat for two (plus occasional friends and family) that will be as safe and comfortable in the tropics as in the high latitudes we are more accustomed to. In my case 15 years as a sailing instructor and professional charter skipper and wildlife researcher, in Louise’s four years aboard our existing boat, plus a female eye for details I would undoubtedly overlook or dismiss—wrongly—as unimportant.
During my working career I skippered vessels as diverse as a sailing trawler, 72ft sail training ketch and for the last nine years a 39ft cutter. All have helped to inform our view of what will suit us. And like most sensible people we have cultivated a magpie eye for filching good ideas, so we believe that our new home will be both original and new. But as the old saying goes, all that means is that the parts that are original are not new, and the parts that are new are not original. And maybe that’s no bad thing—the sea doesn’t change and evolution, not revolution, probably makes most sense.
But what we both agree on is buy well, buy once and keep it simple. Anyone who has ever worked on even a modestly complicated charter boat knows that cheap and weak gear never lasts, always breaks at the wrong time, and that to opt for less than the best always results in a life of endless drudgery fixing/making/mending. And whilst that ability to repair is vital, constant practice doesn’t just make perfect, it can also ruin an otherwise pleasantly challenging pastime. We’d rather be cruising!
So we have taken the plunge, and our new boat has just begun to take shape. And, no, we’re not building her ourselves—we’ve both worked long and hard to get this far, and we want to get going—the clock doesn’t go backwards. But we have had the luxury of working with an Agent and Builder who are broadly sympathetic to our needs (and occasional demands!). Our choice of boat is (to some) unusual, and maybe wouldn’t be your choice either, but we hope you’ll nonetheless find it of interest to follow our trials and tribulations as ONVI 435 No 104 Forever Changes takes shape in the Alubat factory in Les Sables D’Olonne, France.
Over the next months we’ll be writing a
regular update right up until she’s launched, and beyond. And we hope our
travails may help inform you if this is your dream, too, maybe even inspire
you, but never—hopefully—bore you.
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Choosing A Suitable Boat, New Versus Old
There is a strong argument for buying a used boat for long distance cruising. The purchase price is initially more affordable, the boat often comes with a fairly full inventory, and may be well sorted out and ready to go.
An OVNI 435 being framed
Such boats do exist, but experience suggests that the reality is more likely to be just the opposite. The price, which on the face of it may seem attractive, often proves to be less so once the replacement of worn and obsolete equipment has been factored in—refits are never cheap. If your ambitions stretch beyond normal horizons then the equation becomes even more complicated, as suitable boats are few and far between. And upgrading even a well prepared stock boat to meet the needs of a totally independent cruising life will come at a premium price.
The desire for a metal hull narrowed our range of options further. Over several years we’d looked at many steel boats that might have fitted the bill, but all had what might be termed fatal flaws—no insulation, worn out equipment and rust, rust, rust! Such experiences began to divert the search from steel towards aluminum. At the same time more and more highly experienced sailors had turned to this light, durable material for their craft, especially where high latitudes were the destination—think S/Vs Aventura III, Hawk, Morgan's Cloud, Northabout, Pelagic Australis, Seal, amongst others. Their reasons for making such choices were highly instructive and chimed with our own thoughts, so the search began for a suitable aluminum boat.
Aluminum boats in the UK are very rare indeed, although far more plentiful in Europe. Boat builders in France have long seen the benefits of alloy construction, and the Dutch have followed suit, building on their mastery of the art of building in steel. Excellent used boats do come on the market, but we always seemed to hear about them too late—good boats at sensible prices were snapped up, and we undoubtedly missed a couple of beauties. At the same time, the usual mismatches in terms of our baseline, non-negotiable design features came up time and again.
Scrutiny of the prices helped to concentrate the mind—these boats hold their values incredibly well, a good thing if you own one, less so if you are looking to buy. When we focused on a couple of likely boats, worked out the cost of upgrading them to our requirements and added the inevitable bit extra, there was nothing much between them and a new boat, price wise. When we were faced with buying someone else’s compromise, however good the boat, the decision was made—we’d go for a new build. At least, too, with a new boat we stand a chance of having several years of relatively trouble free cruising.
So far we are
happy with that decision. We have been able to build in many desirable
custom features at remarkably little extra cost, one of the major advantages
of building in alloy, and working with a builder who has done it all before.
And we have had a major say in the interior, rig, deck and systems to create
a boat that suits us from scratch. Time will tell whether we have got it
right.
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A Boat Built to Travel
For us the choice of boat was dictated by our need for a traveling base camp for our wildlife photography interests, as much as for recreation. As the places we wish to visit are generally remote from civilization, we need a craft that can go virtually anywhere, for extended periods, and be as self-sufficient as possible—something like an ocean going 4x4. We think that the OVNI 435 more than fits that bill.
All OVNIs offer the benefits of aluminum construction, including high strength to weight, resistance to penetration and abrasion together with integral fuel and water tanks. Combine this with the simplicity of modifying many elements of the construction and thus producing a semi-custom boat at the price of a good production boat, the package is attractive. In terms of what can be changed, the rule of thumb at the builder seems to be that if it has been done before, or will not materially slow down the production line, then it can be accommodated at modest or no extra cost. As ours will be OVNI 435 number 104, the design improvements and suggestions of the previous 103 buyers will ensure ours is as near to perfect as we can hope for.
Of the models on offer, the 435 has the most positive attributes of the range for us, including many “traditional” features such as a well-stayed cutter rig, a skeg hung rudder and protected propeller. The size is right for two of us to handle on our own, as well as being big enough to make a comfortable home with adequate tankage and carrying capacity. The sail plan is modest and well divided, and so should be easily manageable, important for us, as we both have backs that have seen better days!
A well protected rudder and prop are essential for cruising in remote waters
The 435 draws 2’6” with the plate up, 8’4” with it down, and with a flat run along the centerline of the hull will sit upright when dried out on a level surface. Both plate and rudder are hydraulically controlled, and have an ingenious safety device in the manually operated pump, where copper plugs are designed to rupture in the event of either foil striking an object, allowing them to swing freely to avoid structural damage.
The benefit of true shoal draft like this opens up many cruising areas, and is ideal for the exploration we have in mind. Not only that, in many wild places, the ability to anchor further in can make a huge difference to comfort and safety in bad weather—with deep draft you are often sitting just too far out from shelter, sometimes exposed and uncomfortable. And it also means that in the event of maintenance or cleaning of the hull, you don’t need to head for the nearest marina Travelhoist, but simply find a suitable place to take the ground—autonomy, once again.
As for the looks,
well you either love them or hate them: unpainted hulls may look drab,
but mean no maintenance; chines are not everyone’s cup of tea, but add
great rigidity to the structure; and so on. We think the 435 looks great—chunky,
purposeful, and as Bill Tilman was fond of saying “fit to shunt ice”. She
certainly does it for us.
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Making the Most of Aluminum
Aluminum has many obvious attributes as a construction material—high strength to weight, durability, lack of maintenance—but there are other, subtler benefits that aluminum can offer, especially if starting from scratch. Careful thought at the planning stage to take advantage of that potential is time well spent.
It is an easy material to work in. Louise has just returned from France where she has inspected our boat at the completion of welding. From start to finish it has taken around six weeks from a pile of plate to a finished hull and deck. She was also able to view the completed joinery waiting to be dropped into place. This is, in effect, “furniture”, and not structural, a benefit in terms of its long term integrity, as well as ease of access for periodic inspection of the hull or in the event of any structural damage that might necessitate welding. It also demonstrates how an aluminum yacht in the hands of the right builder need not end up being colossally expensive.
Aluminum lends itself to one-off design internally too. In a GRP yacht the position of bulkheads is still to some degree dictated by their structural role, making the interior layout far less flexible. With aluminum, bulkheads, heads units and so forth can in theory be wherever you like. The only limiting factor for us is the factory philosophy of limited modification at sensible cost—but if we had wanted a custom built interior, we’d have to be prepared to pay for it, so we’re very happy with what we’re getting.
The OVNI has a number of features that make good use of the potential of aluminum construction. All tanks (fuel and water) are integral and welded into the hull, and have removable plates to enable cleaning and internal inspection. All of the lead ballast (3.5 Tonnes) is encapsulated in plastic and then plated in to the bilges. In the event of the hull being pierced in any of these areas, only a tank or a ballast chamber will be breached, hopefully averting a potential loss. At our request the builders extended the forward bulkhead behind the anchor locker to full depth, welded and watertight, giving us a crash bulkhead against collision with any floating objects—that ought to help us sleep easier!
Our new boat - welded everything!
Where we have
really tried to exploit the benefits of alloy construction is on deck.
Our motto is, “if it can move—weld it”. Not just from the point of view
of structural integrity, but also to avoid leaks and corrosion caused by
dissimilar metals where fittings have been screwed or bolted on. So all
grab rails (and we have plenty), dorade vents and tangs for deck gear are
welded. We have also had fitted welded breakwaters around both forward
hatches to protect the seals from deck sweeping seas, as well as a solid
breakwater where the cockpit dodger will be mounted. All have been easy
and cheap to achieve at this stage of the build—the watertight bulkhead,
complete with inspection hatch cost around $300, for example. An additional
anchor stern roller in line with a sheet winch was easily incorporated,
a simple custom boat hook holder mounted on the stern arch, tangs for webbing
davits—simple things, but worthwhile we feel, all adding in their own
way to a functional, sturdy, and (hopefully!) leak proof home.
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