CORSICA 15R

Sports Car Performance on the Water

 

Over the past couple of years, I have taken a break from my boat design work. During that time, I’ve been able to reassess my connection to the craft. The last boat I designed was the Europa 20, which is a trimaran meant for vertical strip foam construction with sandwich style, infused epoxy/glass laminates inside and out. The Europa is a boat for very fast day sailing with a very light hull and a very big rig. A boat that is not for everyone, to be sure, as it requires a level of skill that the average guy does not typically cultivate in the course of experiencing their recreational boating interests.

In stepping away from the larger, more powerful beach type multihulls, I came around to the desire to produce a smaller, very quick and sensitive boat that would appeal to recreational sailors and not just those guys who want to blast around with their hair on fire (though I do suspect that in the right hands, this boat will do just that). The new design had to be easy to build with standard, marine plywood/epoxy/glass techniques that did not rely on exotic layups with spendy carbon cloth. (Well, maybe the carbon will sneak in there a bit on the beams for the guys who want to play with a bigger rig)

Looking long and hard at the smaller skiff-like hull designs I had done before, such as the Montage, I decided to draw the new boat in that same general size, but with a very different approach when it comes to how the boat achieves its performance potential. Where the Montage has a relatively spacious cockpit capable of taking on a couple of adults, (or a parent and a couple of smaller kids) the new, Corsica 15R trimaran would be for one adult (or accomplished kid) designed solely for a unique, one-up sailing experience within the small beach multihull genre.

Corsica15R bow high water wMuch like a performance dinghy, the Montage has a wide, flat sailing surface conducive to the planing of the main hull. It’s more like an outrigger supported dinghy in that regard, than it is a trimaran. Certainly, the Montage fits within a grey area when it comes to defining nomenclature. The Corsica 15R, however, would be very much like other high performance trimarans with very slender, easily driven hulls that have the potential to achieve boat speeds well beyond the typical displacement design. There is no main hull planing function going on with the Corsica 15R. It is all about pure, straightforward achievable speed via well-known multihull design thinking.

As a result, the boat has minimized clutter when it comes to excessive high-tech trickery. With that approach, the Corsica 15R is also going to be a boat that has much lower maintenance requirements in order to keep it in top sailing condition, as well as a much lower realized cost to get it on the water and ready to sail.

If you are into cars, as I am, then think in terms of a nicely pumped, Mazda Miata, type of boat that would be a cool, weekend canyon racer for one person. A boat that could blast around the local waters in a good breeze and give chase to other small, fast, multihulls being sailed by crews of two.

The result of this conceptualizing process is the Corsica 15R. The C15R is a boat of modest, marine plywood build techniques and is very light weight for its generous sail area. With this boat, the normal sailing position would be the skipper, semi-reclined within the main hull, driving his machine like an F1 Grand Prix car. In this configuration, the boat is designed to utilize foot pedals for steering, leaving the hands free to work the sheets. But, that’s not the only way to sail this boat. Owners who wish to sail in a more conventional multihull style, can sit-up out of the cockpit and onto the main hull cockpit gunnel, or even the trampoline surfaces all the way out to the ama, where they will steer with a tiller extension.

Corsica15R above w

A construction style in multichine, 4 mm marine plywood, allows the boat to be assembled in a well-understood fashion that will go together quickly. With a subtle placement of minimal stringers and sufficient bulkheads, the C15R becomes a strong main hull shell that can absorb the loads from its sizeable rig, turning the power of the sails into forward thrust in the water.

There is no fully enclosed transom on the vaka hull. The cockpit deck is slanted gently down and aft for automatic self-draining, such as is seen in sport dinghies and larger race boats. A collection of bulkheads under the cockpit deck provide structural support and watertight compartments ensuring that the boat will not likely sink even if large sections of the bottom are torn out from an underwater hazard while smoking along in a gin clear lagoon.

The demounted boat can be assembled easily by one person. The gently gull-winged akas are built with a glassed box beam core.  The inboard ends of the akas slide into tapered sockets in the main hull and are levered in place with stainless waterstays to make ready for sailing. This, tapered socket technique prevents binding while assembling the boat, while providing a solid, hassle-free and weight minimized demounting system. The leading edges of the akas are smoothly shaped foam blocks that are glassed onto the box beam to provide an aero component, as well as creating reduced drag from waves and spray. The akas are hard fastened to the amas as a complete assembly that is easily removable from the vaka hull. The trampolines stay mounted to the akas and amas for transport and only have to be hooked and tensioned to the main hull during assembly.

The mast is a stick from a Hobie 16. I specify the addition of a set of spreaders from the Hobie 18 mast to stiffen up the H16 mast to handle the additional righting moment generated by the Corsica design. Naturally, I’d prefer to see fresh sails in something like fully battened, Pentex laminate, but builders on a tight budget could also work with a loft service to tweak a reasonably fresh Hobie 16 main and jib and do just fine. The addition of reefing points on the main are strongly suggested, as well as the use of furlers for the jib and spinnaker/screacher. For those who desire fresh sails for this boat, I would recommend the folks at Whirlwind sails in San Diego, California. http://www.whirlwindsails.com/

Corsica15R bow water w

A removable carbon prodder sets the tone at the front end of the boat. The stick originates as a carbon windsurf mast, so it is easily found on the used market and equally replaceable, should it get poked into an unyielding environment. For trailering, the sprit unpins, slides out of its socket and is stowed in the cockpit for transport and storage.

Corsica 15R Specifcations

LOA                                         14’ 11”  (4.54 m)

BOA                                         13’  (3.96 m)

Displacement                         650 lbs.  (294.8 kg.)

Sail Area (upwind)                 218 sq. ft.  (16.17 sq. m)

 

Spin                                       142 sq. ft.  (13.19 sq. m)

Mast Length                           26’  (7.62 m)

Draft (board up)                     1’  (.3 m)

Draft (board down)                42” (1.07 m)

The mast is raised by the traditional beach cat method of physically lifting the mast with the base pinned to the mast step, or by utilizing the long daggerboard in its trunk as a form of a gin pole. A forward hoisting line is led over a pair of sheaves at the top of the daggerboard and down to the hand cranked winch on the trailer. Mechanical leverage quickly raises the mast so that the forestay can be fastened to the bow, stepping the mast securely. You can see a few photos of the process at Brent’s L7 trimaran site:

http://home.comcast.net/~ritakend/site/?/page/Mast_Raising/&PHPSESSID=864f3404e3f46ed29dd99b863018fc1d  This is a very simple way to raise a mast should you need to avoid the trad lifting exercise for one reason or another.

I chose to not go with tricked-out, curved lifting foils in the amas due to construction complexity and added cost for the builder. Foils of this type are hard to build correctly by hand, as are the needed curved trunks in which they slide. Instead, the boat is equipped with a daggerboard that is inserted through the deck of the main hull in front of the mast which angles aft to exit the hull below the waterline. A daggerboard and trunk of this type are much simpler forms to build and orient in the hull. It is also just one main foil, where lifting foils need to be made in pairs, one for each ama. Lifting foils also need complex control mechanisms to retract and deploy the foils and they have to work from the cockpit remotely with the foils mounted way out in the amas. The needed controls are an interesting problem when the boat is 13’ in width and the driver is semi-reclined in the main hull.

Note: I’m not against an owner who might want to experiment with foiling for this boat, even if it is just foil assist and not full flying. It would require a lifting t-foil style rudder and twin Bruce style foils in the amas, or, if a person is really accomplished as a composites builder, they could make a pair of matching c-foils for the ama. The owner just needs to know what level of additional work is involved and at what skill level they need to perform in order to get the desired result.

Corsica15R beam water w

If you are on a budget, the rudder and headstock from a Hobie 16 will work just fine for the Corsica with some mods to the tiller. The more deluxe, Rudder 25 system from Dotan will also work well, should you have the coin.  http://www.dotan.com/  If you plan on pushing the boat hard, then a longer blade will be required, or you can get yourself invested in the process of putting a rudder on each ama and have stunning control at your finger tips. On the down side, that change will cost you a bit out of your pocket and at the launch ramp in setup time… though I can see a nifty rig with light alu tubing and the use of snap buttons as a cool solution.

The Corsica 15R will be a light boat built from familiar materials. It should be a fairly simple building experience for the owner and will fit comfortably into any typical garage space, making it easy to find a building location. It will quickly assemble for sailing and be hassle free with minimal maintenance required to keep it in top form. It can be towed behind any compact car on a typical beach cat trailer and when demounted for travel, is road legal anywhere in the world. On the water, this boat should be quite quick and behave with predictable, pin-point sailing manners. With the skipper slung comfortably in his reclined cockpit seat, he will be decently protected from the effects of the weather and sea state while tearing around his local waters.

Chris Ostlind

Lunada Design

Collage

Another Trimaran/Skiff … Bigger, With More Power

 

Collage aft obl 5x7

 

Well, you had to know this would happen…

When the Montage Skiff/Trimaran was introduced, the Lunada Design website was absolutely flooded with an ocean of page hits every day right after the article was posted. I received several dozen personal query letters regarding the boat and sizeable slice of them were directed at the potential of a bigger version of the Montage.

The concept of being able to build your own boat and rig it with a used mast and possibly even used sails, (if they are in good enough condition) had struck a chord with the homebuilding community. The creation of a larger version of the Montage would take the specified rig choices up into the much more commonly found beach cat rig sizes and make the business of finding a used rig in great shape, a whole lot easier. After pencilling a collection of thoughts and running some rough numbers on the potential, the idea came into focus as the 18′ Collage.

The new boat is very much like the smaller Montage in many ways. The Collage has very similar lines, with the exception that it can be quickly Collage-Montage profile comparison 5x7identified by its subtle, reverse bow profile. It has  a virtually identical purpose and the same, functional conceptual pragmatism for the homebuilder. The plywood version and the strip-built design both have the same bow profiles. This profile is also applied to the amas of both build styles. I wanted to give the boat a bit more of an aggressive look without taking it too far in the direction of the out and out racing multihull designs currently in vogue.

The ama shapes, especially on the smooth hulled variation, borrow other design cues from the modern performance dedicated French designs of VPLP, as well as the very cool work of Nigel Irens. The transoms are nudged in the direction of a triangular shape, while retaining some of the typical beach cat, flat-topped U-form feeling. The volume concentration is well-forward, with the foredecks being much more rounded to provide rapid shedding of water. These shapes will help to reduce the tendency of multihulls to pitchpole when sailed hard.

Collage bows tight 5x7Collage bow obl w

 

Breaking away to some degree, from the single, build style of the Montage offering, the Collage is presented as a fully strip built, smooth hulled version, as well as a multichine plywood version. These choices will give builders the ability to work with the material choices and aesthetics they prefer. I am also looking at the potential for a foam cored sandwich laminate boat using the vertical strip technique, though that iteration will probably come around a little later in the process.

Collage bow obl 5x7

Collage Specs

LOA 18′  ( 5.48 m )
BOA 14′  ( 4.26 m )
BOA main hull 41″ ( 1.04 m )

Sail Area
Main 163 sq. ft. (15.14 sq, m.)
Jib 55 sq. ft. ( 5.12 sq. m. )
Spinnaker 161.5 sq. ft. ( 15 sq. m. )

Displacement 1000 lbs. ( 454.5 kg. )
Weight 380 lbs. ( 172.7 kg. )

The Collage meets all the same design criteria as does the Montage, except it’s longer and wider, has more sail area, carries more crew weight and yes, it’s going to be faster in the right hands. Faster… sometimes this term can be kinda self-defeating when speed claims are made compared to another boat. When it comes to recreational boats, I’m of the opinion that speed is a relative thing based on the overall design brief of the boat in question. In the case of the Montage and Collage designs, speed is one of the attractive elements as long as it is kept in perspective with  just what the use application will be from day to day. From where I sit, this will be primarily recreational purposes.

Collage wide angle 5x7

The Sail Area to Displacement ratio ( SA/D ) for each of the boats is as follows: The Montage is 31.56 and the Collage is 34.88 With both of these boats being sailed at near max displacement, I give the nod to the Collage, based on waterline length, as well as the ability to punch through wave conditions that will toss the Montage around to some degree.

I would like to see this pair of boats ( Montage and Collage ) blasting around in the hands of skilled sailors. There’s nothing quite like the feel of a performance boat and the way it can deliver the exhilaration of a spirited ride. But… I’d also like to see this boat out on the water being used by families while they have a really fun day on the water with, maybe, a somewhat toned-down speed blast tossed into the mix every now and then to get the kids chirping.

Collage bow very low 5x7

I’m looking at the potential for the Collage to create a new beach and/or lake sailing culture in which energetic hot shoe dudes, as well as young sporting families, can all mingle on the beach, out on the water and share a communal BBQ after the day of sailing. I grew to maturity on the beaches of SoCal watching the brand new Hobie Fleets do this very thing and it was a lifestyle that perfectly fit my beach kid way of thinking. It would be great to see that happen once again. Could this take place in 2009? Hey, I don’t know the answer to that one, but it is fun to think of the boat and its owners in those terms.

There’s a lot going for the Montage/Collage design approach to support such a social event concept. Both boats are affordable to build, they are easily trailered by even sub-compact cars, they make use of “experienced” parts that can be had on the open market for pennies on the dollar when compared to new parts and they are boats that are easily sailed on the first day. This last part is important, as the boat will attract more enthusiasts when they see that they can be sailed with what pretty much passes for beginner’s skills. Just because it can go fast, does not mean it has to be sailed that way. As the owner’s skills grow, the boat’s potential will be there waiting for him.

Collage flying hull 5x7

As a way of introducing the Montage and the Collage designs to the homebuilder market, I’d like to offer free plans to one person. This builder should be able to show me that they have a very strong interest in either design and are willing to build the boat as I supply the plans in accordance with their progress from the previous plan set delivery.

If interested in this offer, you can write me at: Chris@Wedgesail.com or at lunadadesign@gmail.com and make your pitch. The one chosen to receive the free plans will be willing to provide construction photos of their progress and a brief written description as to how things are going. The personal accounts will be published on this website, Lunadadesign.net so that the readers of the site can follow the projects.

Chris Ostlind
Lunada Design

Montage

Family Oriented Trimaran/Skiff With Performance
Montage bow water w
I’ve drawn a lot of small trimarans in the last seven years, beginning with my A18 for performance coastal cruising. During that time period, there has been an explosion of other small, daysailing trimarans on the market. Several years ago, a new trimaran/skiff hybrid was introduced from a clever group of guys in New Zealand called the Weta.  www.wetamarine.com

 

This boat created immediate appeal to beginning and intermediate sailors. It offers much of the speed experience of a high performance skiff in a stable and predictable platform that is really tough to capsize. The Weta is one of the first boats to encourage family participation and reintroduces the waterborne fun of the beach sailing culture, established way back in the late 60’s with the intro of the Hobie catamaran.

A brand new, factory built Weta goes out the door for USD $11K. Realistically speaking, this isn’t an in surmountable amount of money for a factory produced, brand new carbon trimaran. It is, however, quite a lot of money for most casual recreational enthusiasts and the folks who like to build their own boats… especially when you consider the rugged economic conditions we all face these days.

So, I decided to take a whack at producing a set of plans for a homebuilder’s version of a Weta-like hybrid
that could be Montage aft up wbuildable in the neighborhood of $5600 ready to sail with a new mast, sails and trailer. I’m calling the new boat Montage, as it is an assemblage of concepts that fill the slot between a performance skiff and a small, quick trimaran. This boat will appeal to sailing enthusiasts from kids to codgers who just want to get out on the water and have a fun and fast experience without breaking the bank.

The estimated $5600 figure represents a boat with a whole host of brand new parts. For the clever builders out there, the Montage could be even less expensive if they can find a used 470 rig, perhaps a used small craft, or beach cat trailer that could be modified to fit the hull design and even a collection of hardware in good condition. The Montage is a very light boat at right around 235 lbs., so you do not need to buy a heavy duty trailer.

Montage bow obl wAfter a dozen different sketches of boats that fit the general design motif, I settled on a plywood multichine hull design that had virtually the same dimensions
as the manufactured version.  When I projected the hull panels to a two dimensional layout, though, I saw that I was going to be wasting a good bit of plywood by going with a 14′ 5″ boat that mimicked the dimensions of the production version.

I went back to the drawing table and reconfigured everything so that the longest hull panel was going to just fit on a couple of sheets of marine ply laid end to end. The main hull also got just a bit wider in the process of lengthening the boat. Where the factory boat uses carbon fiber on foam cores for its structure, the Montage will be a 4mm marine plywood design with full fiberglass/epoxy sandwich laminates inside and out. The foredeck and the cockpit seating transitions are strip-built in Red Cedar to give the overall appearance of the boat a smoother, more organic feel than straight plywood panels.

Montage R bow obl

The amas for Montage came from a 16′ trimaran design that I had already done and required minimal re-design to work with this boat. The amas are also designed as multichine ply forms with pretty high volume shapes well forward and a water shedding deck form that will helps to keep them riding high even when driven hard. Ama displacement is 100% of the all-up boat weight when sailing.

Montage Specifications

LOA                                   15′ 6″
BOA                                   12′
BOA main hull                  41″

Main                               110 sq. ft.
Jib                                      38 sq. ft.
Screacher                      102 sq. ft.

Displacement                 650 lbs.
Weight                             235 lbs.

The aka beams are anodized aluminum instead of carbon tubing. The inboard ends fit into fairly burly sockets in the hull and are held in place with quick release pins. Flat deck flanges on the ama ends are welded in place and bolted to the amas. The amas are removable from the aka tubes for repair or maintenance, but otherwise stay mounted, along with the trampolines, as complete units.

The mast is also anodized aluminum. The boat uses the same mast section as the 470 dinghy, which is a Proctor Cumulus section. This mast is available on the used market with a little bit of hunting around. If you want it all and have the money, then there’s a very cool, filament wound Forte carbon spar available with very close specs to the Proctor that will rock your world. http://fortecarbon.com/

Making these two changes from the benchmark, all-carbon Weta to an aluminum spar and tubing keep the costs down, with but a slight weight penalty over all-carbon parts. If you find a used mast, the savings will be even more substantial.

Montage Above wThe mainsail and the jib will be built in Dacron instead of a more expensive fiber/Mylar laminate sail. The jib is a self-tacking blade. The main is a boomless design, which will keep head bonking incidents out of the picture while sailing. The screacher is furled from the bowsprit for simple convenience.

I have found that the more expensive sailcloth laminates are capable of driving the boat just a bit faster, but for the average recreational sailor, they will hardly ever make a difference compared to more forgiving sails in Dacron. Dacron is much easier to maintain, lasts longer, is a lot more tolerant of UV exposure and can be repaired by any sail loft wherever you go. If the builder of the Montage really wanted to, they could buy a set of sails in something like Pentex laminate instead and they’d have that hot, performance boat look that some desire along with just a bit more zip under sail.

The overall design of the foils and their operation is pointed directly at the needs of a recreational sailor. The boat uses a centerboard for ease of use
and pretty much no-brainer beaching. Likewise, the rudder is a flip-up style unit that eliminates the problems of hitting Montage aft low wunderwater objects. The foils will be built with template shaped cedar cores having a white ash stringer for stiffness and then glassed for durability.

The aluminum aka tubes will be sold pre-bent and ready to install on the amas. If the builder has access to a good mandrel bending facility that can handle the OD/ID specifications of the tubing, they can fabricate their own tubes to supplied specs.

The Montage is designed to be a really fun day sailing machine that can generate near performance skiff sailing speeds while offering a hugely stable platform for recreational sailing. Construction of the boat is very straightforward in marine plywood with glass/epoxy laminates and can be easily built by any sailing enthusiast who has household handyman skills with tools. The Montage has been created to offer homebuilders an opportunity to enjoy this style of family sport boat at a completed cost that is far less expensive than the manufactured version.

CHRIS OSTLIND

Lunada Design

FRESH TAKE ON THE SOLO16 S

A safe, speedy solo cruising craft for adventurous souls

Solo16 S w

After a lot of input from readers of this site, I have completed the modifications to the Solo16 S design that reflect many of their
expressed interests.

The Solo16 S now has a bit more displacement as a direct response to suggestions for the use of a small 2 hp outboard and some spare fuel. At the same time, the vaka hull was given additional beam above the waterline and the shear was raised some to allow for mods to the amas.

Solo16 aft obl w

The amas, themselves, were made slimmer and taller, while retaining the same volume. They now have a slight vee section which gives the boat a progressive resistance increase as the amas are pressed heavily in a gust.

To complete the changes, a sporty all-weather soft cabin has been designed to allow the owner a chance to sail in a wide spectrum of conditions. The new cabin is modular in its approach with the ability to address a multitude of sailing situations.

Solo16 S weather cabin wThere is a folding dodger setup forward with a large PVC window for full visibility. A removable Bimini top extends aft, covering the entire cockpit from rain and a relentless sun. Side panels can be put in place as needed to protect the crew from hard spray, or to further enclose the cockpit. A reversed dodger is positioned at the aft end of the cockpit completing the full cabin system.

All panels except the Bimini have generous window areas which are backed by micro mesh screen that is small enough to keep out the No-See-Ums. The PVC windows are zip-out removable and the screens can be rolled-up for maximum airflow through the cockpit. The complete enclosure system allows the owner to mix and match the panels as needed for the best protection from the elements.

Solo16 S weather cabin aft wThe Solo16 S is a lightweight, trailered boat with demountable amas. The aka beams stay mounted to the amas, along with the trampoline surface. The aka ends fit into composite tubes which are bonded to the vaka hull and the side hiking platforms.

When setting up the boat for sailing while on the trailer, the owner simply lifts the ama assembly, rotates and places the ends of the aka tubes into the matching vaka openings and slides the ama into place. The akas are fully seated when their internal, spring loaded snap-buttons click into place. The entire ama assembly is easily handled by one adult with modest physical strength.

Solo16 S folded for trailering

In the trailering mode, the complete boat does not exceed 68″ (1.7 m) in width, falling well under every trailer width limit in the world.

Chris Ostlind

Lunada Design

Neo 21 Sliding Beam Catamaran

Modern design, enhanced stability and creature comforts, along with remarkable utility make for a stunning trailerable beach camp cruiser for passionate multihullers.

neo-aft-in-the-water-5x7-400x300

Hobie Alter introduced the Hobie 16 catamaran in 1969 and the sailing world, as it was known, hasn’t been the same since. In 1992, with many of the beach cat lifestyle crowd having families of their own, the Hobie Cat company introduced a new boat called the Hobie 21 SC (Sport Cruiser) that was aimed at the more leisurely needs of beach cat cruising, rather than the well-known, hull flying beach cats.

5

The 21 SC was, as you might guess, 21′ in length. As a fixed beam design, it was limited to the typical, US trailer legal width of 8’6″. It featured a built-in cooler, an outboard mount and it had a 29′ mast carrying 222 sq. ft. of sail area (main and jib).  The Neo 21 is designed to accept rigs from a wide variety of beach cats making for a reasonably easy job of obtaining a really good used rig for the boat. This feature, alone, will make for a very economical boat to build.

The design calls for a main and jib rig between 218 sq. ft. and 250 sq. ft. (20.26 sq. m. – 23.22 sq. m.) You can go bigger than that and no doubt some will, but you’re on your own. The larger rigs may require an adjustment in the placement of the daggerboard, but that’s about it.

Getting away from the discussion on how big of a rig can be run on the Neo… I wanted to explore the potential of a cruisy-style beach cat that would be more stable for a young family. The Neo and its collection of studied variants, has been in development, off and on, for the past couple of years. The Neo is much more about spirited cruising potential than it is about shredding up the local waters with all-out performance, as one would typically see from a big beach cat with a high performance rig. The boat, while sporting a fairly wide, 11′ stance, is also carrying more weight than a typical performance cat of this length. Slightly heavier, yeah, but the Neo will show a very nice turn of speed, to be sure.

Neo-aft-obl-w-400x300

There’s a faster boat hiding within the base philosophy of this concept, but it’s going to be coming along a bit later and it will have a distinct set of design rules for a much different purpose.

The typical beach cat tends to suffer from a small collection of problems that make them somewhat less than desirable for coastal, camp-cruising type applications and a full day on the water with no breaks.

At the top of the list of things that could be better are the issues of:

  1. Low bridgedeck clearance, which is the primary cause of slamming in a choppy seaway.
  2. Fixed primary stability that is a lower design priority compared to the go-fast regime at which they excel.
  3. Restricted leg placement arrangements while seated on what is normally a flat hull deck and adjoining trampoline surface.

The design of the Neo 21 addresses each of these basic issues, as well as solving a few additional problems, making for a really fun, fast and stable beach style cat for coastal cruising and camping.

Bridgedeck clearance
 
When cruising at more sedate cruising style speeds with both hulls in the water, the bridgedeck clearance of the typical beach cat is decidedly lacking. Beach cats have less clearance because the hulls are drawn to be as small as reasonably possible. Hulls with minimized surface will reduce aero drag when the windward hull is flying. Smaller hulls will also weigh less than those with higher volumes and exposed surfaces. Lastly, when you get the windward hull of a beach cat up in the air, any concerns about slamming wave tops with the trampoline deck tend to melt away.
Neo-bow-deck-clearance-5x7-400x300
 Cruising style cats are not meant to fly the windward hull, save for very controlled circumstances. As a result, the Neo hulls have been increased in height over other 20-21′ beach cats to provide 16 inches of bridgedeck clearance. This will significantly reduce pounding in choppy conditions and at the same time, provide a much drier, more comfortable ride. Comparing the hull height of the Neo 21 to that of a Hobie Miracle 20, you can clearly see the difference in water level clearance.

Striking a balance between the typical big beach cat and some other cats with much more flared hulls, the Neo experiences a bit of both design advantages by having mildly flared hulls as a key element of their design.

Because the hulls are not meant for sleeping quarters, or sitting within, the flare angle can be kept down, reducing the effect of wetted surface drag when pushing through a seaway. Similarly, because of the mild flare, the Neo has a lot more reserve buoyancy than a beach cat. In real terms, this means a boat that will be able to strongly resist the tendency to want to bury its leeward bow when pushed hard, or when taking a surprise gust. Not only will the skipper of the Neo 21 get more time to take action to avoid a pitchpoling incident, but he’ll have more of a safety cushion to stay way from the scenario in the first place.

Cautionary Timeout: There isn’t a boat out there that can’t get tossed by wild conditions, or poor seamanship. If you decide to build the Neo 21, you will need to observe and respect all the same danger points of sailing to stay upright and moving towards your destination. Even though the Neo 21 is capable of filling many of your boating dreams, it is not a magic carpet that can get you out of any jam you manage to ignore too long.

Let’s face it, one of the really great advantages of having a multihull, is the speed benefit over a monohull of the same size.  The Neo design presents an attractive hull design that is decidedly cruising oriented while retaining the key aspects of outstanding performance under sail, or motor. Just as important is the aesthetic impression of the Neo hulls. They just look fast… even when sitting at anchor.

There’s more, though, to efficient boat performance than the design of the hulls. One of the key elements to overall performance and truly good upwind sailing potential is the efficiency of the jib. Jib efficiency is very closely tied to the tension of the forestay and the issue has to be addressed specifically for beach-style catamarans.

Bigger cats place a large beam at the bow and equip it with a seagull striker to maintain high levels of forestay tension. While the Neo 21 is equipped with a beam at the bow, it is as much there to provide a nice taught forward trampoline perimeter, as it is to help with forestay tension. The real power behind the forestay tension on the Neo is obtained through the central pod, which runs the entire length of the boat.

 

The Center Pod

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The single most striking design element of the Neo 21 is the center pod, which extends from the bow of the boat at the forward beam, all the way aft, to just past the aft beam.

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For the past several years, many of the high performance, Decision35 racing catamarans on Lake Geneva, Switzerland, have been built with these centerline pods and I found the potential to be very advantageous for the applications I had in mind for the Neo 21.

 

Much like the ultra high-tech, D35 cats, the center pod on the Neo performs a number of design, structural and utility tasks for the boat, not seen on other beach cats of this type. This pod acts as a structural beam fore to aft and provides solid fixing points for the sliding beams that connect the two hulls. The center pod also allows for the rig to have a very taught forestay, which properly shapes the leading edge of the jib for much better pointing upwind and sail shaping. Because the pod absorbs a good deal of the compression loads of the rig, it serves to lessen the compression loading on the main beam. The smaller total load on the main beam allows for the removal of a dolphin striker from the engineered beam, allowing for faster setup and take-down times on the launch ramp.

Above the deck, the trampoline deck volume of the pod serves as a storage compartment for the anchor and ground tackle while cruising and also provides a really nice back support for sitting out on the forward tramp surface. Well aft, the pod provides a very strong, outboard engine mounting point behind the aft beam sliding structure.

So, is this just a case of,  “Hey, why not just build a trimaran?”

Not in my opinion. The pod is significantly smaller in height, as well as beam, than any trimaran hull might be for a boat this size and is very easily and quickly constructed. The application benefits of the form far outweigh the time, money and weight to include the pod in the build of the Neo 21. I see the pod as a clever means for spreading the powerful loads of the mast, as well as a way to comfortably keep the entire boat aligned while spreading, or compressing the beam at the launch ramp. The center pod is not a principal flotation form, though it will provide for a decent degree of buoyancy, should the Neo be capsized.

Increased Stability
 
The Neo 21 is equipped with a sliding beam system for maximum utility. While the boat does fall under the US limit of 8′ 6″ for trailering, the real magic takes place when the sliding system is employed, spreading the sailing beam of the boat out a very stable, 11′ overall. The typical arrangement of a beach cat is a one piece  main beam and one aft beam, both of them fixed in length. With some exceptions, this design approach pretty much locks the beach cat into a standard, 8′ +width in order to take advantage of the existing trailering limits in the US without extra road fees. (the European trailer limit is 2.55 meters (8.36′) and in Australia the limit is 2.5 meters (8.2′) )
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The images above show the graphic difference between the Neo when it is compressed for trailering and the full beam of the boat ready for sailing. It’s pretty clear from the renderings that this is a much more stable boat than the typical beach cat with its fixed beam.Neo-beam-comparison-2-w-400x300

In place of these fixed beams, Neo uses three structural beam elements. The full width, removable forward beam is positioned at the bow and serves as the mounting point for the forestay, as well as the forward limit of the bow area trampoline surface. The main and aft beams are each made of two, equal diameter tube sections, which slide past one another through fixed containment structures mounted to the deck height surface of the center pod.

The trailering configuration of the Neo 21 is very simple after lowering the mast and removing the rudder system.

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1.) The forward beam sections are removed from their half sockets on the inside surface of each hull and the alignment slot in the center pod

2.) the main and aft beams slide past one another in the two containment structures and the hulls slide toward the centerline until the boat is at trailer legal width.

3.)The sliding beams are then pinned in place for trailering and the forward beam tube is bundled with the main sail and boom.

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As discussed previously, the standard Neo 21 is designed to use the rig (230 sq. ft. of sail area), sailing hardware and rudders from a donor Hobie 18 . H18′s are available all over the place at near fire sale prices, so the really expensive stuff for a homebuilt boat, the rig, sails and rudder systems, are easily obtained.

I am suggesting that the Neo be equipped with a set of mast stabilizing lines that mount to the mast at the rigging hounds and are fastened on each side of the main beam. There is a gin pole that drops into a socket in the forward part of the center pod that serves as the lever to hoist the mast while the stabilizing lines keep the rig from falling off to the side during stepping. The forestay is used for this procedure with a rope extension that is quickly clipped into place on the forestay shackle. The rope is led to the hand winch on the trailer for the hoist.

Once fully raised, the safety lines are unclipped and fastened to the mast and the forestay is shackled in place. This is an easy, simple method for mast stepping that has virtually no danger of getting out of control and can be done by one person, if they are strong enough to safely move the mast into the correct position for stepping.

The hull pans and the rounded deck surfaces of the Neo are strip built in Western Red Cedar, or other suitable softwood. The large, planar hull sides are constructed from ¼” marine plywood. This gives the Neo the look and feel of a production boat with rounded surfaces employed where they matter most, the in-the-water hull shapes and the rounded, wave shedding surfaces of the decks. The easily fabricated hull sides of plywood have smooth, softly flared runs, bow to stern.

In the cockpit, the inner edges of the hull decks are notched back at deck level to provide a nice leg angle when seated on one of the center facing cockpit lounges on each hull. These seats are removable for transport and have backs that fold down for a more compact storage unit in the hulls.

There is also a fully rotating, contour shaped skippers chair located just forward of the aft beam. This chair gives the skipper a full, 360 degree view by just spinning around with his feet. Want to face forward awhile and talk to the other folks on the boat while comfortably driving… you can turn the seat any way you want it while having your fanny cradled in comfort. The owner/builder can even install a contour shaped seat with a reclining back feature. The guy doing the driving gets to pick how he wants to sit and in what direction he will face.

The hull decks have nicely spaced access hatches and ports for easy storage of everything from the camping gear, to a built-in cooler.

The main deck is a hard, flat surface that serves as perfect platform for tent pitching when at anchor. Along with the area provided by the notched deck surfaces, the owner can comfortably pitch a 7′x7′ domed camping tent for remarkable comfort for a family of three. I’ve seen this size of tent available for under $100, making for a great value… if you pick one that can hold together for several seasons.

If the owner so chooses, they can also drop 4′ stanchions into built-in sockets at the four corners of the deck/hull area and hang a large awning over the entire bridgedeck, supported by a topping lift, or boom gallows. Weather covers of this type can be anything from bone simple to pretty darn luxurious, complete with no-see-um netting, depending on the desires of the owner. The advantage is that the tent volume can be extended out over the decks of the boat on each side, making for a much bigger space than a 7×7′ tent. Like anything else about boats, the final choice will be determined by preferences… and budget.

Admittedly, this whole, tent camping thing on an open deck catamaran is not for everyone. For those individuals/families who do not care for this approach, the Neo would probably not be a viable boat for your needs unless you are looking for a big, quick, day sailing beach cat.

If you don’t like camping, I would suggest the build of my Gato Especial design at 21′ LOA. The Gato has a full cabin with interior room for a queen-sized bed, a small galley and a compact space for a port-potti that can be screened for privacy.

The deck surfaces of the Neo are hinged, accordion fashion and folded to a vertical position for the sliding together of the hulls for trailering. As an alternate thought, the solid floor could be eliminated from the design in favor of a dual trampoline surface. The tramp would be built with a simple aluminum tubular frame that also hinges on each hull and folds into place for sailing. Just like the solid floor, it would also be folded up and out of the way for the sliding beam process. It would provide a lot less side windage while being trailered, but also allow for spray and wave action to reach the bridgedeck while sailing. No free lunch with design choices.

The cockpit notches in the main hull also provide strong creature comfort for long sailing sessions, as the crew can bend their legs while sitting on the removable, fold-down seats on each hull. This feature immediately takes the boat away from the typical, tiring beach cat arrangement of having your legs straight-out on the trampoline surface for hours on end.

The tramp forward is made from any of several suitable trampoline products which have small wind and wave resistance, while still providing a nice place to lay out on a warm sailing day. For reference, as well as a highly regarded supplier, you can check-out the various types of trampoline surfaces that are available.http://www.multihullnets.com/product/product.htm

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You can go with the typical, beach cat style trampolines made from a mesh-like woven cloth, but

I’ve seen very good knotted, or woven net tramps as well as surfaces made of flat

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webbing, sewn at each cross-over point for totally secure footing. Cost, use and durability will guide you to the proper decision on the tramp surfaces

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