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

SHOULD I PATENT MY WIDGET FOR THE BOAT INDUSTRY?

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Let’s just imagine that you have been recently slaving away in your very cool, very modern version of Geppetto’s workshop out in your back yard and you’ve come up with something that is every bit as nifty as Pinnochio… only your cool thing is a truly innovative doo-dad for the boating industry.

Suddenly, the heady rush of riches and fame come charging through your brain and it hits you like a huge explosion! “My GOD! I need to get this thing patented before someone finds out about it and swipes my wonderfully inspired effort.”

Well, hold on just one minute there, Pilgrim. Perhaps you better give this article a full read before you rush off to the nearest Legal Office where they practice Intellectual Property Law where simply sitting down with a qualified patent attorney is going to nail your pocket book for some serious cash…. just to talk it through.

Here’s my take on patents for boat stuff in general. All you guys out there in TV land can have your own take on these things and I encourage you to make your points known. It won’t change my opinion on the matter after 25 years of fiddling around producing video programs for start-up companies who blew a large wad on their chase to “get a patent in place” and then fitfully protect the same thing.

Real simple, patents can cost large amounts of money. The more complex the claims in the patent application, the more money it takes for some patent attorney to make use of his selective knowledge of the arcane language of the patent application, seacrh for prior art and establish that your “invention is enough different from what came before and commission a set of equally arcane drawings to show what the item looks like in graphic terms… and then file for the patent itself with the U.S. Patent Office.

If patents could be submitted in normal language, there would be many fewer reasons for hiring of a specialized, Intellectual Property Attornies at $300 an hour to write this stuff for you. After all, who knows the way the nifty new device works better than you?

For most patents, the big cost is in the process of the “patent search” so that you can quote many examples of prior art in your submission and the logical progression of inventions that may, or may not, have led to your device. Again, this is all part of the game, should you need to pursue some violator of your precious patent in a court of law. Notice how it, once again, comes back to a court scenario so that you need to hire another attorney to stand in for you? This is the key part to the argument.

After all, the patent by itself, is nearly worthless, save for the so-called ego boost one might get from being a “patented inventor”. It’s just a crappy, official looking document on your wall that just might impress your buddies when they come to visit. (see the ritualized document at the head of this article) Without the desire and resources, as in MONEY AND TIME to pursue the violators, the whole patent process is absolutely worthless as a business enterprise. Some folks will tell you that it adds value to your invention. Well, that part might be true if you think that the thing is about to set the world on fire and you will see checks for millions of dollars come rolling into your hands. If it’s not of that magnitude, then its value is pretty much up to you and your sense of self as an “inventor of stuff”. These are things that the world, in general, does not find very compelling… well, unless you are Brad Pitt, or somebody like Bruce/Caitlyn Jenner.

My take is that for the average guy, who has developed some really cool thing for the boating industry, the best thing to do is to take all the money that they would otherwise toss at a patent and save it for something else. The intellectual properties attorney, the draftsman who does the nifty and similarly arcane drawings of the invention and the fees at the patent office; Save it for another, more important thing….  May I suggest…. That would be to use that money to invent the next best thing for the boating industry, OR… better yet, spend it on the marketing of the first really cool thing, so that they can achieve something like market penetration and hopefully, a dominating market share before the Chinese rip you off and copy your design and build it with far lesser materials and then flood the market with the fresh idea which you slaved to create.

There is one exception to this patent thing for boaty kinds of things. That being the absolutely inconceivable potential that your patented device can properly be licensed out to a big time boat company for MILLIONS of dollars. Really, MILLIONS… as in the kind of money one might get for inventing a new medicine that cures five kinds of cancer. You know, the kind of cash machine idea that would move the desktop computer industry into the next millennium… Otherwise, it’s a huge waste of time and money and it will give you a false sense of confidence that you really have something worth fighting over.

It is just so damn easy to make a ten-percent improvement in an existing invention that, in the words of the Patent Office, moves the invention forward, that it’s ridiculous. Want to know how simple in actuality this all is… just go to a big tradeshow for any industry, you select the one you prefer, and watch the hordes of guys from Asia running around with digital cameras, taking pictures of everything under the sun that looks even mildly interesting.

Now, what do you suppose those dudes are doing with such a fervent sense of purpose? The answer is, and I hate to dump it on you nice guys who think otherwise, but they are swiping your ideas. They are shooting photos of your stuff so that they can take all that home and reverse engineer it. They will make some very small and virtually irrelevant change in the device and come roaring back next season (or sooner in some cases) with their own brand of your hard-earned super cool, next best thing. Now, don’t get me wrong that it’s only those Asian guys who are doing this. Everyone is doing the same thing, or they will soon find themselves without a job. Well, they will, unless their company has a very high degree of ethics and they have their own super smart inventor dudes who don’t need the leg-up.

Think you can stop that? Think that it matters to them if they “might” get sued by you? Think they worry about your limited financial resources that totally inhibit your ability to mount an on-going legal procedure? Hey, my friend, this is modern business which is the civilized equivalent of open warfare without the explosions. If your figurative army is too small, you can only try to make a hasty retreat and lick your ego, literally.

All this boils down to the fact that you should be spending your lovely time, your creative problem-solving genius inspiration and going down to the shop and inventing that “next best thing”. This will, once again, put you ahead of the market and force the other guys to play catch-up to your glowing capabilities.

Does all this make me sound bitter and hateful? Do you think that maybe I had one of these gotcha experiences myself and have the wounds to prove it? Well, I don’t.

I just worked within the community of hundreds of creative industrial design types, making video-based marketing presentations for them and THEIR really cool, patented new gizmos. Most of them, if their invention was, in fact, really cool, were unceremoniously shoved to the corner of the heady, trade show sales floor by a bigger outfit who brazenly nabbed the idea and had the resources to go full-tilt with it…. Within two years!

If you insist on going for the patent, may I be so bold as to recommentd a really thorough and accurately written book about that very topic..? It’s called: Patent It Yourself and is available from all the usual resources such as Amazon and Barnes and Noble booksellers.

I have this book myself and found it to be so beautifully composed and presented that I routinely use if for reference in these matters. This book will save you many hours of stupid goose chasing and it is written by a guy who knows his stuff.

PatentItYourself You, the good guys, had no fall-back position and no fresh ideas, as all your time and money had been spent on chasing that “Hey, I’ve got a patent” concept. Eventually, most of them accepted full-time jobs at the firm which nabbed the invention, where they learned to keep their mouths shut and take that lovely paycheck home to pay for food and clothes for the kids.

There isn’t much that would suck more than that.

My very strong suggestion if you do create something decidedly powerful for the boating, or outdoor recreational market is to LICENSE the thing with one of thoe huge companies who would find the device to be compatible with their corproate efforts. Do make sure to get a Non-Compete document signed with the firm you pitch so that they won;t snag your idea and force you to hire an attoney to get them to stop producing it behind your back. Have them decide if a patent is appropriate, front the costs of all the manufacturing tooling, find the fabricator and defend the patent should someone screw around and try to knock it off. All this stuff is their playground, not yours and while this is going on, you still collect a royalty check for every one of them that goes out the door and maybe even a significant design fee for the actual creation of same.

Brilliant. The wife and kids will find you as their own private superman who brings home an enhanced paycheck to save for college and go on real vacations where you guys can actually VACATE.

These are things that don’t suck at all.

Chris Ostlind

Lunada Design

Strider

Dual Mirage Drive powered, two person launch

Duckworks - Strider

Some time back, I encountered an ex-pat American, now living in Melbourne, Australia, by the name of Mack Horton. Mack wanted to build a two-person boat for cruising the harbor and waterways of his hometown, Melbourne. He was looking to propel his boat with a twin setup of the wonderfully innovative Hobie Mirage drive designed by Greg Ketterman. I really liked that idea as I had already done a few different boats that were Mirage capable, but they were all solo boats. This design concept opened a new door for me, as it would allow me work out the balance and weight issues for a twin drive and once built, I could also discover how much more speed potential might be available beyond a solo drive.

I had a hull in mind from my portfolio that would need to be “massaged” just a bit to get the form stability and low-speed performance for which I was looking. The boat had to be able to handle potentially large boat wakes and small chop of the open regions of the harbor and still be easily driven by human leg power.
Duckworks - Strider
I was looking to achieve some of the lines of a classic launch with reasonably low windage and yet, enough freeboard to ward off the possible conditions. Surprisingly, the hull form came directly from a previous boat shown  at the Duckworks Magazine, the A18, canoe/trimaran.
The A18 hull had a very strong bias towards higher speed potential with only a nod to being driven at slower speeds, so a slimming process had to take place in the forward and aft sections of the hull. Likewise, the beam of the hull was pulled out some to give the boat a solid degree of form stability so it could ride the wakes of passing freighters in the harbor when taken abeam.
I sent the plans off to Mack and he promptly got to work on the boat at his favorite spot for boatbuilding, the Melbourne Wooden Boat Center

Cut to the Chase

Mack has now finished the boat and has had it out on many outings. He’s learning a lot about boat trim and optimal placement of the heavier pedaler for best performance and handling. Besides the still photos showing the boat on the water, Mack has also provided a pair of video clips showing the boat underway.

 

 

 

Clearly, Mack’s Strider, Ripple, is showing itself to be a pretty fast boat when being propelled by two average people. This is being done from a semi-reclining position with hands free, while enjoying the sights in the Melbourne harbor and adjacent waterways. Here is a link to an article I wrote for Duckworks Magazine that shows the GPS track and speed data achieved by the Strider design: http://duckworksmagazine.com/08/reports/feb-mar/index.htm  This is pretty heady stuff for a human-powered vessel intended for casual cruising and not blistering speed.

Mack reports that one of the ubiquitous dinner cruise boats, that you see in just about every harbor of the world these days, pulled alongside and challenged both he and his friend, Justine, to a little race. Off they went with Ripple easily leaving the cruise boat in the dust. Let’s overlook the fact that powered cruise vessels of this type have strict wake generating spped limitations…
Later, as shown in the video clip, Mack and Justine took-on a fully crewed Dragon boat. Dragon boats measure 40 feet in length, 4 feet in width and carry 20 paddlers, 1 drummer, and 1 steers person. On average, these boats weigh 500 pounds. Understandably, Ripple could not quite match the speed of the Dragon boat with twice the waterline length and 20 paddlers. Perhaps there could be a triple version of the Strider in the future? One that is longer, more slender and much, much faster.
Duckworks - StriderThe Strider design calls for a very straight forward stitch and glue build method in 4mm marine plywood with glass/epoxy laminates inside and out. The twin Mirage trunks sit cleanly in the hull allowing for a comfortable seating arrangement for two persons and their day pedaling “stuff” such as binoculars, cameras, food, drink, blankets, etc.
In the right environment, the boat could easily be used for overnight camping as well, as there is plenty of displacement capacity for more gear, should the owners wish to use their boat in that fashion.
I expect to see these boats being equipped with Bimini covers and small forward dodgers. The interior hull sides will probably be lined with neat rows of mesh bags to storage of the small things that make for a really nice time on the water, such as: sunscreen, lip balm, mosquito repellant, drinking water, snacks, camera, VHF radio, GPS, etc.
Maybe you have a cabin/cottage on a lake where the general store is across the water, but a short distance, but to walk, it would take an hour to get there. Strider is an excellent, human powered boat for a trip like that. An enterprising person could equip her with an all-weather set of side panels to mount under the Bimini edges, allowing trips to the market in any conditions, short of a full-on gale. (Check out the last video clip above)
The boat is cartoppable, much like a large canoe would be, but I’d advise the person doing the loading be reasonably fit and/or have a really sweet loading system, or technique, as the boat does weigh right around 70 pounds without the Mirage drives in place.
Mack has kindly supplied some very interesting speed marks for the boat that were confirmed with a Garmin Edge 305 GPS with wireless heart rate and cadence monitors.
Highest speed attained with two pedalers…… 7.2 knots
Highest speed with one pedaler………………… 5.7 knots
Average speed for one hour w/ two………….. 4.8 knots
Average speed for two hours w/ one…………. 3.9 knots
Turning circle for the Strider is 33’

These figures run pretty much spot on with my estimations. They also indicate that the hull has gotten to its, “not gonna go there” speed limit and will be pushing uphill on its bow wave from that point on.

Duckworks - Strider

While underway in Strider #1, “Ripple”, it is not unusual to be hailed from dockside and beasked, “What is it?”, “How does it work?”, “How much does it cost?”, and his favorite… “It looks like it has an engine!”

Response has been very positive from athletes, because it’s fast… and from non-water type folks because Strider is stable, comfortable, dry and “not scary”.

One of the reasons that Strider is so stable is due to the recreationally respectful beam of the hull. I’m working on a much faster version of the Strider design concept, which should pretty much take the Mirage drive out to its theoretical top speed limit.

All in all, Strider is a really fun and stable human powered vessel designed for recreational pursuits by two people. It has the classic look and feel of a traditional launch to it while underway and can easily power-up to get out of the way of oncoming traffic in a crowded harbor, or lake setting.

Chris Ostlind

Lunada Design