by Jeff Gilbert

Schooner Cartaphylla 1999-2004
by Jeff Gilbert

Hull Development

The hull was always intended to embody the East Coast tradition of the fast rakish trading schooner, but it had to be both affordable and ocean going, two aims so at odds that I thought the whole business worth forgetting. But the idea would not go away, and I became heartened about the cost of such a design if the compromises others had used could be combined within a strong simple plywood hull. A few light schooners for sheltered water use had been successfully turned out, and I noticed Garden’s little 20ft schooner-rigged flat-bottomed double-ender Sandpiper, which was so simple the prototype was built by a schoolboy. It seemed all that was needed was to add a strake, turning the flat bottom into a swell-carving vee. I thought of the elegant simplicity of the loose-footed gaff rigs of Wharram’s catamarans, including those in the Schooner rig of his own Gaia, rigs which safely bring the centre of effort low, raising stability and exponentially lowering costs in one fell swoop. I revisited the Aussie “Flying Tadpole” Bolger Light Schooner website, and felt that a stronger, stiffer ballasted relative could be sealed against the elements and make successful, albiet Spartan, passages.

Hence I decided to draw up such a boat and see if there were folks like me who wanted a traditionally styled wooden alternative to the parade of efficient but soulless plastic sloops. Cartaphylla the Wandererer would be a solid pocket cruiser using 3 sheets of plywood as its length – hence just two butt joins/scarfs along a single chine hull 23 feet on deck. I allowed just a foot of overhang each end, forrd to accommodate the de rigeur clipper bow and aft to balance looks, and lighten a largish rudder in order to assist self steering off the long tracking keel.

She was to carry a traditional rig – this suited admirably with its low centre of effort and possibly winchless sail plan. The initial desire for a wonderfully slim replica, almost plank on edge 5300lb hull with just 5 feet of beam, produced interest aplenty, mostly screams from frustrated would-be-voyagers who envisaged mildly useful accommodations, and produced further trouble at the drawing board as she had little sail carrying ability without heavy ballasting.

By this time I had decided the boat would be too small and pretty to carry a tender, and hence would be amazingly shoal of draught at 32 inches to achieve shore access sans dinghy, & enable a beach bottom scrape between tides. A generous lazarette could house an inflatable for the inevitable occasions when one could not nose up to one of those idyllic grassy riverbanks which apparently don’t exist outside of my drawings. (Even the optimistically named Meadow Lark winds up at the Marina with some would –be-Rockerfeller gleefully measuring her bowsprit). This lazarette would add a poop deck element to the style, & remove the dread bucket from the accoms. In correct Naval Architectural terms this would be known as “dramatically reducing the waft”.

So the boat grew in agonised stages from narrow to slender to a final WLL:Beam of 3.5 to which the adjective “slimmish” might precariously append. I added the ultimate proviso that she should fit into a container. Downwind cruises to the West Indies, followed by exploring the islands and shipping home while you return to work would be viable.(Unless like me your job is akin to sailing upwind into a Typhoon of bullshit). In short the ability to ship the boat would be a boon should one need to sell. Cartaphylla was to be her own lifeboat too, super strong and 180 degree self-righting . Quite a challenge on such shoal draught, but achieved in the end by moderating midships flare while keeping the sidedecks narrow, and using high coamings to reduce resultant spray. The cabin top and lazarette “poop deck” are at a level, & provide the vital righting moment between 150 and 180 degrees.

Cartaphylla was intended as a yacht for life, a boat that was affordable, yet at 3 tons able to achieve the load carrying, motion comfort and speed to take a pair of sufficiently obsessed voyagers across oceans. A pocket cruiser which would not only make a trip, but be a point of interest in strange ports. A social icebreaker - everyone loves a schooner, particularly a salty wooden gaffer with jutting bowsprit and a faraway port wearing off its transom. (The gaffs & ‘sprit provide spread more than show, & will enable this little ship to carry more sail on a reach than one could with a tall Marconi rig. One can stand on Cart’s cabin top and reach the centre of effort, but as a result the length over spars is dangerously close to 30 feet. Should this cause marina fee paranoia, a commensurately infuriating folding bowsprit could be devised. I look forward to designing it with all the enthusiasm of a man counting nails.)

To create an able comfortable cruiser it was decided to make the accommodations unfussy, simple and extremely comfortable for two, with a large aft lazarette to keep all that be wet and smelly out of the main cabin area. Laz & cabin sides are linked by a 9” coaming, thus corralling a large, safe self draining central cockpit –a place to laze & enjoy the view with more than the usual degree of safety. In port here is room for a hammock, and a basic hundred dollar A-section tent will reach from windscreen to poop providing privacy and shelter as needed.

Cart in Feet: L0A 29.80, LOD 23.00, LWL 21.27, BOD 7.18, BWL 6.26, FREEBOARD 3.25, 2.00, 2.50, DISP 6200, BALLAST 32%, LCB 12.13, LCG 12.05 DRAUGHT 2.67, PRISMATIC 0.63

Cartaphylla’s major task is to make sea miles on a waterline with a square root of just 4.6! However if we settle for sitting headroom, Cart can sport minimal rocker and a 6degree buttock run. So I’ve drawn a hull with strong leanings towards semi-displacement, aiming for a S/L ratio of just over 1.5 to give 7-knot capability. This is not to say we can do 7 on every point of sail when we please, or ever do it on any point of sail, merely that the hull will allow it given stiff enough ballasting and the right wind and sea states. A hull this short will never be lightning fast without planing, but this one is designed to motor more efficiently than a full-bellied full-displacement yacht of its length.

The way to make passage times is not to go bash your boat bits at her limit, but to make sure she maintains most of what speed she has, to maximise her low speeds. This is where Cart is a winner, being the perfect size and weight to take one of the smallest of diesels such as the Farymann 18w which can bowl her along 100nm in a seaway in 24 hours, running at near peak torque on a comfortable 2/3 revs, and using just 30 litres of diesel the whole day. Many of the popular Trawler yachts guzzle that per hour, without going much faster. So armed with the knowledge of these automotive-like fuel mileages we know Cart. may cover 800nm with a 240 litre tank, & she is designed to carry just that, and a lot more should you wish. Losing an inch of freeboard can double this nominal fuel supply, which could be expanded to encompass motoring the Atlantic with the aid of a watermaker and a calculated safe initial level of overload. Note that the watermaker should be used safely – one must take off with a supply of water and make sufficient water so you always have aboard twice what you need to get to the nearest source at your normal daily run.

The engine space has been allocated in the rear 2.5 feet of cockpit. The correct sorts of motor will be able to assist ballasting by bedding low enough in the hull to run a shaft almost parallel to the waterline. If the budget runs to a variable pitch prop, even more wonders are possible with the chance to motor-sail in “overdrive”, adding to your sail power and motor-sailing on a reach at 6 knots with minimal heel. The designated space is large enough for the larger 12-18HP generation of motors for those who prefer to motor at higher speeds while retaining good economy, and in the very likely event that a diesel is off the budget for the time being, there is space and hull area to perform bottom surgery and site an outboard well in almost the same spot, the shaft being offset to one side of the keel. Obviously the fuel efficiency will not be as good, but it will still be very much on to motor Doldrums.

I believe the decision to bend Cartaphylla to the task of motor-sailing is not detrimental to her pure sailing abilities, as she was initially quite light. The additional weight of engine and fuel is low in the hull and makes for a more comfortable motion. Overly light pocket cruisers, like tiny cars, are exhausting on a trip.

She was always at the light end of the cruising diplacement/length ratio range for decent travelling yachts. More weight cant hurt. The combination of hefty weight and lower sail areas at sea has proven so effective that some of the better stock designs offer a "cruising" package, eg Dehler, while others go straight for it, long tracking keel and all (Island Packet). The additional weight of engine and fuel is low in the hull and makes for a more comfortable motion. Overly light pocket cruisers, like tiny cars, are exhausting on a trip. Cartaphylla aims to leave the dock for a fortnights cruise with SA:Displacement of 16 and Displacement:WLL of 283, firmly in the cruising comfort & safety zone. The idea that she carries a massive sail plan is an illusion created by the sail spread sans hoist, the opposite of the current fashion. One will of course be attracted to the option of entangling oneself to the gills in all kinds of Fisherman & other staysails with wonderful names which are great until you try to put one up or down

Gaff rigs don't point quite as high. She is shoal. She needs bouyant ends (see next para.). Her Prismatic of 0.63 creates a lot of downwind speed with a little lost upwind. It's a fact that she is not optimised for upwind sailing, it would take an entire character change to make a difference. Far far better to recognise that these same factors make her efficient under power, install the economic engine she was designed for, and motor-sail upwind at a really good clip. In trying to optimise her upwind performance we would lose the lot. I'm talking relativity here, I'm not saying she won't sail upwind, she will, but she simply can't have a deep fin, and high aspect sloop rig. The fact is that a lot more sailors would motorsail the slower points if their boats were not abominably thirsty.Yours isn't, so set up with a decent motor you can be there on time.

I was still faced with the problem of getting a boat through the water with a sail plan that put much power forrd. Essentially how to get the water past a hull which needed the bow bulk/lift to carry a sprit and foremast without plunging, After the usual merry-go-round of drawings and calcs I was satisfied that the answer was in a goodly forefoot that cuts the seaway low, eliminating bow slap without losing volume. Carts moderate 19-degree deadrise vee hull also grew judicious flare in the fore sections, in keeping with the “cods head” look of a typical schooner deck plan. Aside from the hydrostatics, the hull looks well, always a good sign. Nothing comes for free, but its been proven on much more radical designs that eased fore keel will compensate for the larger forefoot in bringing her head around on a tack.


Designers whose work I studied around and about the years I spent conceiving and finetuning this little yacht include Chapelle, Parker, Brewer, Beuehler, Garden, Bolger, Herreshoff, Colvin, Crocker, Gustaffson, Bombigher and Devlin. But though I pore over the lines and writings of these fine Gentlemen at length, when I actually get to the drawing board and computer all books have been firmly closed for some time and stay that way until I have a hull. Thus not a line or idea is directly scaled or copied. This I believe is the only way to produce original work. Of course finetuning and comparison is made later, but I at least am able to see that the work is my own. One uses a conventional design spiral to finish the job, but by this stage one usually has a boat sufficiently original & firmed-up to hydrostatically resist attempts to shove its looks toward another’s style. (I imagine this can happen subconsciously). Insistence on originality backed by extensive checks is time consuming, and may be why Cartaphylla’s hull is version 24!

And so we have Cartaphylla, a boat whose profile and plan are slightly reminiscent of the trad East coast schooner, too small to imitate one, but bold enough to relate. She hides a cruising tankage and a motor where the hold of her bigger relatives would have been. A firmly stated forefoot and clean entry flow into a 32 inch draught long ballasted keel leading a full rudder, and her hard chine sections have moderate Vee with high form stability complemented by ballast & completed to 180 degrees by cabin and poop-deck-lazarette. Her sail plan is pure trad gaff schooner, but simplified to a single jib on a furler.

Set up for a perfect safety record, she is designed to carry two EL1000 one tonne Turtle-Pacs, which will keep her afloat indefinitely even after a catastrophic hull breach. The Pacs stow in their own self-opening bags and are fixed firmly to the hull, inflating in 40 seconds from a standard scuba tank. A single $478 Pac will prevent Cart foundering, but one at each end of the boat means unsinkability even if one is damaged in the debacle. Two inflated will ensure you can move about within the cabin to radio for help from the set mounted high on the chart table, and possibly seal the leak before pumping out. This is entirely possible as the lazarette and main cabin are sealable sections, whilst I’m looking into the possibility of sectioning off the forepeak with a little live, scared effort. There will also be a sealed locker for flares, EPIRB and another GPS sealed in Ziploc bags. This wad of safeties cost less in toto than an in-service liferaft, yet are more effective. They convert Cartaphylla into an unsinkable lifeboat which would be driveable under sail and even motor if you are lucky enough to have one dry. Laszlo Torok’s Turtlepacs provide an unshakeable last line of defence against invisible semi-submerged containers, and he invented them after many years of cruising.

Cartaphylla sports the motoring efficiency to motor-sail passages considered timely for yachts twice her size, by eliminating becalmed periods. Loaded for an Ocean Passage, she can be trimmed along the way by some internal ballast along with a honeycomb of boxes below the cockpit, which enable small units of flexible tankage to be moved to one side for those long passage tacks.

The process of designing her was so longwinded that I felt I should document it in the interests of those who do me the honour of building and sailing her. Hence this rather lengthy narrative, which is partly myself ruling off the hull design before I go on to the final sail plan and the thousand details that will go into her furniture-integrated hull. This will happen over the next few months and the first Cartaphylla begins construction in Aug.2004 by Mr Dave Burdecki of San Francisco. My thanks to him, Carl, Dmitri, & a special vote of thanks to Terrell Guillory for his unbounded enthusiasm.

You guys are what this is all about, creating something from nothing, and the sum of us can do what the parts couldn’t. So thanks to all of you, and Chuck himself, and the many people who put up their hand and proved to me that people still have the guts & sense to go to sea in a beautiful cantankerous little wooden ship they made.