Back Bay Sit On Top Kayak

A Modular System Approach to SOT Kayak Sailing, Paddling and Mirage Drive Propulsion

BB Scorpion bow obl 8 w

Sit-On-Top (SOT) kayaks are easy boats on which to learn to paddle. They have none of the “get in the coffin and you are about to drown” psychological identity that one finds in the Sit-Inside boats and they’re amazingly adaptable to a wide range of paddling activities. It also doesn’t hurt that they are pretty straightforward boats to rotomold, which makes them very cheap to produce in large numbers.

I didn’t envision just one boat for this niche in the home-built kayak market. Instead, it came to me that there would need to be at least three models that could address the wide-ranging styles of boating interests in this area of the kayak world. The result was a couple of very clean, SOT models at 14’ and 16’ called the Corona and the Back Bay, respectively. The third model was going to be called the Wahoo, as it was specifically designed for the folks who spend a lot of time fishing with their SOT’s. I’ll get to the Wahoo in the next article.

As a canoe and kayak sailor and a guy who had just been out for a test drive on the Hobie Adventure Island, which is based on their 16’ SOT Adventure model, I wanted to offer my own take on what makes for a truly fun and stylish, sailing SOT kayak. The result was that a fully integrated system of component parts was designed for the basic Back Bay. This modular approach allows the Back Bay to go sailing by simply adding a system of light-weight, easily built elements that quickly convert the SOT to a single aka sailing boat called the Scorpion, OR, to a double aka sailing boat with slightly larger ama volume, called the Doubloon. Of the two configurations, the Doubloon is most like the well-known and highly respected, Hobie Adventure Island.

The Corona and the Back Bay are virtually identical models, save for their respective lengths. For the purposes of this article, I’ll focus on the Back Bay version and all the potential add-on systems I’ve incorporated in the design.

THE BACK BAY SOT KAYAK

BB16 above w

Specifications:
Length overall – 16′
Beam overall main hull – 28″
Depth of hull max – 12”
Weight – 48 lbs. or less
Displacement – 335 lbs.

This boat is built in the S&G style of construction in 4mm marine ply with 6 oz. plain weave fiberglass set in epoxy on the inside and outside of the hull for full laminate sandwich strength. The build process uses external cradles as building supports, ensuring that the hull goes together with minimum hassle when handling the rather slender and longish hull panels. The boat is bulkheaded internally at three key points. These bulkheads create not only integrated strength in the design, but they also cleanly separate the hull cavity into four unique volumes for gear storage and watertight flotation.

The Back Bay can be configured with a large, open tankwell set aft of the cockpit, or built with a watertight, aft hatch cover for internal storage in a conventional kayak style.

Scorpion bow low w

Specifications:
Beam overall – 10′
Weight (est.) – 90 lbs.
Sail Area – 56 sq. ft.
Displacement – 350 lbs.
Draft (board down) – 28″

The Scorpion variant is a Sit-On-Top design for fun sailing, paddling, or Mirage peddling… or all three, as the builder desires. There will be a design for a leeboard mount included in the plans for those who are going to build the boat for sailing. Having the aka gull wing form set well forward permits a full paddle swing arc.  The aka beam connectives to the amas is split into a pair of mounting elements. I did this to make for a stronger, single beam mounting struture. With a single beam design, there is a tendency for the am to want to rotate around the beam, making for a very stressed component that could lead to early failure. By splitting the beam and spreading the mounting points, I have given the structure more resistance to this rotational force, making for a more rigid boat in use. This setup will allow the owner to power sail in light air with both the paddle and the sail providing thrust. With the leeboard swung down for sailing, the owner can do some “power sailing” and utilize the Mirage drive, as well as the sail, in light conditions. The Mirage is capable of boosting boat speed enough that it creates apparent wind over the sail, adding power where there really isn’t enough for sailing alone.

The amas are positioned to optimize capsize resistance when sailing off the wind. The amas do not touch the surface of the water at rest in stable trim and provide only minimal wetted surface drag when underway by paddle or peddle. As soon as the sail is loaded by the breeze, though, the ama on the lee side begins to immerse, firming-up the boat and resisting the heeling moments being generated.

The aft deck can be configured as a watertight hatch with full access to the aft sections of the hull, OR a large, diving tank well with self-draining ports. The cockpit is fitted with self-drain ports under the seat as well as forward, in addition to the daggerboard slot. There is a watertight deck plate just forward of the seat, between the knees of the sailor/paddler to provide secure storage for critical items that may be needed on a routine basis. The foredeck has a watertight hatch cover for bow storage needs.

The rig is a fully battened Dacron sail with two reef points and a multi-section, self-supporting mast which steps into a sealed mast socket in the hull. The mast and boom sections can be aluminum or carbon, as budget permits. The sail choice is open for the customer as long as it can be balanced with the fixed positions for the mast and dagger board. The Cunningham is run to the deck of the gull wing aka to keep the rig on the boat in the event of a capsize.

With 56-sq. ft. of sail on a 90-pound boat, this will be a decently speedy boat without being in over its head all the time in a stiff breeze. I suggest two reef points in the sail to allow for sailing in a wide variety of conditions.

This will be a wet boat at speed, yet there are no worries at all for flooding and sinking, save for a truly nasty trip over a reef that shreds the entire underside of the craft. The bow, cockpit and aft hull volumes are all independent, sealed compartments, as are the ama volumes.

Reentry from a swimming session will be easy with a simple, sling, or rope ladder much like those used by rock climbers, called etriers.

BB Scorpion aft obl 8 wSliding foot pedals in the cockpit control the rudder. The rudder flips-up when it encounters an underwater obstacle, or when beaching, returning, due to bungee tension to the deployed position once past the obstruction.

The boat is constructed in a multichine, marine plywood style with epoxy glass laminates inside and out in a stitch and glue style. Stainless T-Nuts are embedded in the hull deck surface from below to provide a secure set of mounting points for the aka wing. The amas are held in place on the aka tips by large bungees and a notched lock system. This system provides for quick setups on the beach.

You just fit the aka to the foredeck, insert four, 1/4″ threaded stainless screws with comfortable, knobbed grips and screw down the aka wing. The amas slip onto the ends of the aka and you lift the pair of 3/8″ bungees up and over two raised hooks on the aka ends to secure the ama in place. Simple, easily maintained and near foolproof in operation.

DOUBLOON SAILING SOT

Doubloon bow obl 8 w

The Doubloon is the second variation on the central SOT theme of this group of boats. In this design, I am looking to provide a more expansive utility application for the base, Back Bay SOT version. The Doubloon is essentially a solo craft and it carries the same, 56 sq. ft. sail, but the overall potential of the boat is expanded through the use of dual akas and full trampolines on both sides of the Back Bay hull. The rendering of the Doubloon shows a daggerboard inserted down through the Mirage Drive trunk, but in use, I would prefer to have the board mounted outside the Back Bay hull as a leeboard. Plans will be supplied with the leeboard solution.

The akas on the Doubloon are spaced to allow for a full paddle stroke with the boat setup as a trimaran. There are two sections of tubing that span the opening fore and aft between the akas from which the tramp is mounted. The trampolines are designed to roll-up on the outer tube section, much like a window shade and they are deployed by an endless loop of light halyard line. With the tramps fully deployed, the inner tube section lifts up and over a holding pin in the aka and the sailor applies as much tension to the tramp as he feels he needs by hauling-in the endless loop line and cleating it off. If a paddling session is desired, he simply pops the jam cleat and pulls the line to roll-up the tramp on the outer tube section. This procedure applies for both port and starboard tramps.

Like the Scorpion, the Doubloon can be built to utilize a Mirage drive in the center well and the need to roll-up the tramps for paddling is essentially negated, (though it is nice to have the option once in awhile as Mirage drives can be difficult to maneuver in tight places)

The aka beams are held to the deck of the Back Bay hull with the same, threaded knob strategy for quick setup and takedown times. Similarly, the amas are held to the aka ends with hefty bungee cords for the simplicity of use. There’s another, rather invisible, benefit to using the bungee cords for ama mounting. Because they are being held in place through a fairly dynamic hold-down system, the amas can move about, ever so slightly, while underway. This allows the amas to have some structural “give” and the result is that the banging and thrashing that is typically experienced by the ama, is somewhat dissipated through the flex of the joining system.

Doubloon aft obl wThe design similarities to the Hobie Adventure Island are obvious. This boat, however, should be just a bit faster in the water, mostly because it will be much lighter than the rotomolded Hobie. For that same reason, it will also be easier to put it up on a roof rack for transport to the water and a lot easier on the back when you have to take it off the car to store it at home. The Doubloon configuration allows the sailor/paddler/peddler to bring along extra gear, which can be lashed to the tramps in waterproof bags. They can also take along kids, or perhaps someone special, who could lounge out on the tramp surface while lazily sailing along for a sunset cruise on a warm summer evening.

All in all, I think the Back Bay SOT should be a really fun boat to own for warm water/warm weather boating adventures. It has the capacity to carry enough gear for several days out on the water. When rigged with a sailing system of your choice, it can also cover some pretty good distances if the winds are favorable. Plans for this boat and all its variations will be available from this site and Duckworks Magazine.

Chris Ostlind

Lunada Design
Chris@Wedgesail.com

Lunada Bay Double Sea Kayak

18’ compact double sea kayak

Some time back, Fred Gasper, from Haslett, Michigan, and I exchanged a few emails about a boat project he wanted to undertake. He was looking to build a double sea kayak so that he and his wife, Kathy, could enjoy paddling activities together. Fred indicated that he had already built several plywood kayaks and was just about finished with his second stripper canoe, so I knew he would not need an extensive guide through the basics of building a larger boat for he and his gal.

Duckworks Magazine

You can see in the accompanying photo that Fred has pretty well mastered the art of fine woodworking when it comes to building boats. As a new designer with several boats of my own out in the world, I was looking to get connected to another builder who had the talent and the experience to produce a terrific finished boat. Clearly, after taking a look at some of Fred’s prior projects, I was excited to be combining efforts with his capability.

Duckworks Magazine

Fred and Kathy have quite a bit of experience when it comes to taking kayak oriented journeys. They’ve made a few trips to the Pacific Northwest to do just that. They both have a well-developed understanding of what a boat is supposed to do when paddled.

I developed the Lunada Bay design to fill a special niche in the double touring kayak market. The design brief addressed such things as being car-toppable, easily stored in the average garage or basement, able to carry two adults for day paddling and the odd overnighter, highly responsive to turning input and able to track effortlessly. The boat did not need to be able to carry a week’s worth of gear and food or produce a high, sustained speed under paddle, as it was to be a comfortable cruiser for more leisurely outings.

The result was an asymmetric hull design of 18’ LOA with a beam of 28” to be built in a hybrid construction method. Hybrid build style is basically the combination of a marine plywood, multichine hull with a cedar strip built deck. This type of boat takes advantage of the two build styles to offer quick hull construction combined with the natural wood beauty of a stripped deck. It also allows the soft sweeping contours of a stripper on the part of the boat that is most often seen by the paddlers.

In this style, the builder first assembles the hull panels, fillets the hull seams and glass laminates the hull inside and out. He then inserts a series of building stations for the stripped deck process and begins to create the patterns as desired with various colors and species of wood to suit his taste. The hull, itself, provides the strongback form for the stations and soon, the deck is complete and ready to join to the hull with the bulkheads in place.

The cockpit openings are laid-out on the deck surface taking care to measure the Center of Buoyancy of the design to balance the paddling positions in the boat. Once cut out, the cockpits are finished with the construction of the rims and flanges for the paddling sprayskirts. There are probably five recognized methods for cockpit rim fabrication. All of them work and it more or less comes down to how you want the whole thing to look. Something like choosing plaid instead of print for a shirt pattern.

Just last week, Fred and Kathy took their new boat out for a spin on the local lake to see how she’d perform. Fred had been working on the boat, off and on, since mid February. He managed to squeeze-in a trip to the Grand Canyon with Kathy, family obligations, the normal household chores, as well as his regular job, all at the same time. He was more than ready to get the boat on the water. The coming change in the weather probably played an additional role in the urge to go paddling.

Duckworks Magazine

I’m pleased to share with you that the boat performed like a star, ticking off the big elements in the design brief while being put through her paces by Fred and Kathy on an overcast, October day in Michigan. Fred just sent me an email and said, “Tracked and turned great with no weathercocking. Don’t think she will need a rudder. We named her “Travelin’ Louise”

This kind of report is pure music to a designer’s ears. I jumped-up from Fred’s email and took my wife and son out to dinner to celebrate. Everything was great, except my wife wouldn’t let me eat the greasy, garlic mushroom burger I really wanted to order. Seems that even though I can design some really nice, trim boats, I have a long way to go to get my own hull form back to my former nice lines.

Fred and Kathy will need to install the backbands, footbraces, carry straps, seats, deck accessories and then finish off Louise with several coats of beautiful, satin varnish before they put her away for the winter. Fred indicates that the finished boat will tip the scales at just over 60 pounds. I’m really looking forward to the reports from their future adventures in “Louise” over the coming years.

Duckworks Magazine

As an aside, the name Lunada Bay comes from a local surf and snorkeling location from my youth along the beaches of L.A’s South Bay. Where I come from, Lunada is a Spanish word that loosely translates to a moon lit party on the beach. I have spent many warm summer evenings with friends, cooking freshly caught lobsters and abalone on the beach while a full moon lit the sea. I couldn’t think of a better way to use this boat.

Chris Ostlind
Lunada Design

Chris@Wedgesail.com

 

Big Horn Solo Canoe

SOLO TRIPPING IN A VERY RESPONSIVE PACKAGE

Big Horn Bow w

Right up front, I’m going to give a full tip o’ the cap to John Winters, Canadian boat designer, for the inspiration to design this particular canoe. John’s Osprey II S&G design is a beautiful example of a designer bringing his enormous, gifted skills to the worktable. I wanted to draw a solo, tripping style canoe for 4mm marine plywood construction, so I took a long look at the Osprey to see if there was anything I could do differently with the form.

Note: At the end of this article, there is a report from a builder and the results of a committed journey with the Big Horn in the Boundary Waters Canoe Area. Please continue reading to discover a first-hand report as to how the boat behaves in the real world. From a designer’s perspective, it is incredibly satisfying to have independent verification of all the hours that go into the design of a boat like this one.

In Winters’ design, there is a very nice, tumblehome chine along the shear to give additional paddle stroke clearance. I have built boats before that used a similar tumblehome panel and it turns out that they can give the builder some interesting problems when it comes to constructing the hull.

This tumblehome chine is very slender in width, which requires the builder to have a reasonable set of skills to wire it in place prior to filleting or they will end-up with a potentially wavy hull section that just won’t go away short of doing it over. Since I was looking to draw the Bighorn for easier construction for the average guy, I decided to drop the tumblehome panel and instead raise the outer hull panel to maintain freeboard. The result is a six panel hull that is easy to build and nice looking.

Specifications
Length – 15′
Width – 30″
Draft @ 280 lbs. – 3.8″
Weight (estimated) – 42 lbs. (Actual weight 38 lbs.)
Rocker-bow – 2.3″
Rocker-stern – 1.8″

 

Big Horn Aft wThe hull shape is asymmetric in form with the widest point (and it’s center of buoyancy) just aft of the hulls’ midpoint. The hull also has decidedly enhanced rocker fore and aft when compared to traditional canoes of this size. These two design features give the boat very solid, straight-line tracking, as well as wonderful response to turning stroke input from the paddler.

At full, 350-lb. displacement load, the Bighorn has just less than 8” of freeboard amidships. I don’t see this kind of load in this boat unless the owner is going out for a very long solo trip and needs to carry a lot of gear. More likely, you’ll be seeing an all-up, ready for trouble, load of around 290-300 pounds, depending on the weight of the paddler. I figure this boat can be built at right around 42 pounds, providing the guy with the resin doesn’t get too generous with the glue.

Big Horn Above w

The seat setup in the renderings illustrates my take on an integrated unit recognizing the typical canoeists needs when out paddling. There’s a comfortable, sculptural sitting area much like the tractor-style seats one sees on the Wenonah canoes. It is coupled with an integrated pocket on one side for camera/binocular/etc. and on the other side… a circular, net bottomed opening to hold the beverage of your choice. (Ever had a can of coke tip over in your canoe while paddling because there was nowhere secure to hold it? Makes for a fun clean-up session, doesn’t it?)

If you don’t care for the integrated seating system, you can always use the traditional, woven caned seat, a simple, stretched canvas platform or a woven-webbing seat. For that matter, you could always buy a tractor seat from Wenonah.

Outside the typical description of a solo canoe introduction, I decided to include a little extra teaser for those so inclined. I drew a set of outriggers specifically for this boat.

Big Horn with Small Amas w

They aren’t fancy in appearance, but they are very simple to build, easy to use and they provide enormous stability to the boat if you’d like to fish, shoot pictures, take a nap, shoot birds, etc. If you were so inclined, they can also be used with a modest sail rig to allow the Bighorn to be sailed like a trimaran, though don’t be expecting these amas, or the suggested sail rig size of 30 sq. ft., to provide much more than a pleasant sailing experience. Still, it could be fun on the right body of water.

Water Test Report by Stan Heeres

Sunrise-on-the-Boundary-Waters

Build process documented along with the first trips out on the Boundary Waters Canoe Area

The complete web record of the Heres build is currently not available. I’ll search for it and locate what I can of the document.

 

Stan Heeres’ recent comments as follows:

“I purchased plans from you for the Big horn a few years ago. My son and I built the canoe and have since been on 2 Boundary Waters trips with it.
I promised you that I would detail the building process. I did and am just finishing the presentation up and will post it soon.
I have also built the John Winters Osprey (both the strip version and the plywood version). Here are a few details”

Strip Osprey

Lightest(34 lbs), receives the most comments by a wide margin (it looks really good), slowest of the 3 and hardest to keep in a straight line of the 3 at speed.

Plywood Osprey

2nd lightest lightest(36 lbs), very functional but does not get the comments, 2nd fastest and stays in a good straight line.

Big Horn

Heaviest(38 lbs), glides like a dream, Kevin, who uses it, will effortlessly pull away from the other canoes, tracks straight as an arrow.

Cherokee-Morning

 

It’s pretty clear that I am proud of the boat and how it has turned-out for an experienced canoe builder. Being able to say that one of my boats can effortlessly pull away from a design created by a known master in the trade is exciting. That it also has terrific tracking manners when loaded and out on serious water, really makes all the design considerations worthwhile. Stan, thanks so much for the really kind words on the boat. I’m really looking forward to Kevin’s report.

Solo 12 and 14

 

I have developed a new, personal trimaran for small adults and kids called the Solo12. This is a car toppable boat that is meant to sail with no facility for human power other than hauling out the spare canoe paddle and getting with it. The total displacement is 300 lbs. all-up and should tip the scales at about 130 lbs. before getting wet. So, there’s room to wiggle for a wiry dude who wants to tool around in quiet waters and have a blast in a semi-reclining position. Steering is via a pair of pedals and cables to the rudder cheek block, much like a kayak and all the sail controls are fed forward so there’s no need to hike out at all.

The sail area is 56 sq ft. The amas are generously sized to avoid getting out of the cockpit except to hang-out on the beach with friends and have some lunch. Lateral resistance will be provided by a side mounted leeboard on a swivel mount. This will give the boat plenty of upwind lift while being a safety oriented feature that kicks up and out of the way for beaching, or encountering underwater obstacles

The aka tubes are aircraft aluminum and will be segmented with the same spring pins and fitted ferrules you see on take-a-part paddles, so that the amas will reconnect right up next to the main hull for transport and storage. A very compact unit for putting on the roof of your car and going off to the beach, or lake, for some fun.

The build is 3mm marine ply with a full layer of glass outside and taped joints inside. Easy to build, easy to move around the launch site and perfect for learning to sail with little kids as they can sit between your legs and learn how things work. Later, the same kids can take the boat out on their own and there will be no fear of them tipping over unless a tornado hits the area.

There is a companion model at 14′ LOA for slightly larger sailors, all within the car-topping attitude that this boat represents. The SOLO 14 has an optional ama design that allows the removal of the leeboard as the lateral resistance will come from the underwater fin shapes of the amas. This keeps the stuff hanging in the water to a minimum while still allowing a decent performance capability. fewer moving parts will mean simpler maintenance and less stuff to possibly break while out sailing. The rendering above shows the finned amas in place.

Chris Ostlind
Lunada Design
Chris@Wedgesail.com

Rocky Point Sea Kayak

Rocky Point-lunada_bay

I grew up just a couple of miles from the Palos Verdes Peninsula along the coast of Los Angeles County and would often snorkel in those waters for abalone and lobsters with a group of my friends. One of the first “boats” I ever worked on, a leaky, 12′ paddleboard rescued from the heap out behind the main Lifeguard station in Redondo Beach, was used to explore the area with my buddies. Later, we cobbled together a catamaran of our own making by screwing together two of the paddleboards down on the beach and paddling both of them out to our favorite dive and play area.Guarding the northernmost entrance to Lunada Bay is Rocky Point. The waters around Rocky Point, which is the northern limit of the famous big wave riding area known as Lunada Bay, can be anything from totally benign and calm, to a full tilt, out of control melee of oceanic surges and thundering waves. When I started to design boats, I instinctively drew upon locations from my boyhood watery exploits and the name for this sea kayak, Rocky Point, came from this familiarity.

The Rocky Point is designed as a very fast, no-nonsense expedition touring boat with the capacity to carry the necessary gear and stores for an extended stay away from civilization. Obviously, with its narrow beam, this is not a beginner’s boat. Experienced paddlers, though, will settle-in quickly to its gently lessened stability and be able to make the most of the very small frontal area and very long waterline.

The prismatic coefficient of the hull is set to .55 which will allow the paddler to reach and hold a very fast cruising speed. The boat should be equipped with an expedition class rudder to provide a gentle assist in turning as the hull has reduced rocker from my other sea kayak designs and turning was considered a skill for the advanced paddler for whom the boat was created..

Length Overall
18′ 6″
Beam Overall
20″
Length at Waterline
18′ 5″
Beam at Waterline
19″
Displacement
300 lbs. at design waterline

Chris Ostlind
Lunada Design
Chris@Wedgesail.com

 

 

 

 

 

 

 

Driving Sodebo w

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

NAGARE 21′ AND 17′ MIRAGE DRIVE SPEEDSTERS

Making use of Mirage Drive propulsion with more efficient hulls designs

 

Nagare 21 Bow Obl w

Nagare  (nah-ga-ray) is a Japanese word meaning Flow.

The two boats in this group are 17 and 21 feet in length and are known simply as the Nagare 17 and the Nagare 21. Both designs make use of the popular Hobie Mirage drive for principal propulsion with the 21 footer Nagare 17 bow obl wbeing a double Mirage setup and the 17relying on a single Mirage.

Both of them are configured as trimarans with fairly small and unobtrusive amas designed to give the boats remarkable stability in a wide range of conditions while allowing the vaka, (main) hull to be decidely slender for more effective drive through the water.

The Nagare sisters also have incredibly narrow waterline beam numbers that, when coupled with their fairly long hulls provide for very easily driven hull forms for high efficiency per unit of energy applied.

I expect both boats to operate at the very high end of commercially available paddled boats of the same length, beam and weight. So, yes, they can go pretty quickly, but that’s not the real purpose.

The real benefit of the design genre is through the ease with which they are propelled at any given speed, compared to other boats of their size. This efficiency translates directly to those using the boats as less tiring for miles covered, or greater speed with the same effort as other, wider designs.

Because the propulsion is derived from the largest muscles in your body, the leg muscles, rather than the arms and shoulders, there will be less fatigue for each mile traveled. Because leg muscles are so much bigger than arms, they will be able to do more work in a given period of time, making for longer possible trips, as well as the mentioned lower fatigue issue. With a less fatiguing effort, more people will be able to enjoy the experience of being out on the water for daylong adventures.

NAGARE 21 DOUBLE
SPEED AND STABILITY FOR DOUBLE RECREATIONAL BOATERS

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The Nagare 21 uses a set of amas, mounted on a pair of simple, anodized aluminum tubes with quick release snap buttons holding the sections together for easy disassembly for car-topping. If a trailer is used to transport the boat, the beam of the Nagare 21 falls well below trailer maximums, so nothing special needs to be done to take the boat to and from the water. Two Nagare 21’s can be trailered, or car-topped, by removing one of the amas and placing the main hulls close to one another on the racks, or trailer. The removed amas easily fit inside the hulls and they are ready to go. The whole affair on the rooftop is very much like a pair of sea kayak doubles. Because of the length, I would not mount a boat this big on any compact cars. You would be very likely to rip the rack right off the roof in strong side winds.

Steering is by means of a simple, flip-up style kayak rudder with control lines run through the hull to a convenient steering lever in the cockpit. I suggest the SeaLine SmartTrak rudder system (do a search for supplier), the P-41 Multi-purpose rudder from Onno Paddles http://www.onnopaddles.com/onnocomponents.htmland the Feathercraft rudder system for hardshell boats. http://www.feathercraft.com/accessories/rudders-hardshell.php  These are really great rudder units and will give excellent steering control with minimum drag.

NAGARE 21 SOT OPTION

This boat can be built with a full cockpit tub so that it functions as a Sit-On-Top kayak with full drainage through the Mirage drive openings. Auxiliary drain ports are located in the tub for rapid removal of any water that comes in over the side of the hull. I suggest the SOT option for warm water users, with the more traditional kayak style, Sit-Inside hull form for those who will be using the boat in colder water, or more frequent inclement weather.

The SOT version has internal bulkheads for support of the SOT tub, along with the capability of adding a small circular deck plate for an additional watertight compartment in the cockpit that is perfect for small items, such as cameras, wallets, car keys, etc.

The SOT variation is an optional element to the base plans. If you wish to built it as an SOT, drop me an email at my regular email address and I’ll get back to you.

ROUGH WATER USE

This is not really a boat that is meant to go out in rougher conditions, such as those where a full-blown sea kayak might be right at home. It’s meant for quieter waters, such as lakes, bays, harbors and bigger rivers. It can take a session in 1 or 2 foot breaking surf, but I would not expose the boat to bigger waves, especially in a shore break scenario. You may find yourself out from the shore a bit when the wind comes up, producing steep, choppy waves. The basic Nagare 21 will handle this easily because only the cockpit will be exposed to swamping. The amas will keep the boat stable while you pedal to shore, or a quieter place on the water, where you can bail-out the boat and continue.

It is a perfect boat for sightseeing, bird watching, fishing, photography, and just simple, energy efficient cruising with near bomb-proof stability (you can stand up in the boat while out on the water without your partner coming completely unglued, for instance).

The Nagare 21 is a fast, comfortable and unique boat for a couple who like to get out on the water, but do not want to hassle with the business of capsize that is present in other types of boats, such as kayaks and even canoes.

NAGARE 17 SINGLE
A NEW STYLE OF SOLO BOAT FOR TROLLING FISHERMEN

The solo version of the Nagare series has some very different twists, compared to its bigger sister. It has the same, highly efficient and easily driven, slender hull technology, the same set of trimaran style amas well aft for big time stability, the same generous cockpit opening and the same convenient utility for car-topping or lightweight trailering.

The design elements that set this particular boat apart from its sister craft is that the Nagare 17 has a very special capability when it comes to fishing.

AFT FACING TROLLING

Anybody who builds the Nagare 17 and intends to use it for fishing will probably be knocked-out by the potential for facing aft while trolling. Imagine using your legs to quietly drive the boat forward while you casually set trolling rigs, eat a sandwich and keep an eye on the fish finder… all while keeping an eye on the rigs you have set, with them easily at hand?

Nagare 17 bow obl trolling mode w

This is the signature utility development with the Nagare 17, designed specifically, for fishermen. It works like this…

The fisherman loads his boat, drops into the forward facing seat, hits the iPod for his favorite tunes and jams out across the lake at a remarkable speed for a human powered boat. He zips across the lake in virtual silence because he’s driving a very skinny and efficient hull with no engine sounds. Once he arrives, he’s going to make a few sneaky trolling passes with his Mirage drive pushing him along over that monster crew of Pike that are hanging around on their favorite piece of structure. Wham! Fish On! and the day starts with smile on his face.

If you’ve ever fished from a typical Sit-On-Top, you know that you have to face forward while trying to look over your shoulder while trolling. Hook-up and then you have to swivel around, grab the rod and go after the fish. All the time you are doing this, you have to balance the boat carefully, because the whole tamale could go over and end your day right then and there.

Well, that’s how you used to do it, anyway.

With the Nagare 17, you can take it to a whole new level of fishing pleasure. The Nagare 17 is equipped with twin Mirage drive trunks. When driving the boat forward and facing forward, the Mirage drive is dropped into the forward trunk and a tractor-style seat is dropped into the aft trunk with the seat bottom resting on the top of the trunk.

To convert the boat to aft facing trolling and fishing, you simply stand up in the boat and swap the Mirage drive for the aft mounted seat plug and the seat then goes to the front trunk… facing aft. With the Mirage drive still set to drive the boat forward, you simply sit down and start pedaling, slowly, up to your desired trolling speed.

Now, you can watch your fish finder, GPS and your trolling rigs while you continue to tool along at your favorite speed for nabbing the fish. Get one on and simply work that rod while continuing to face aft. No twisting around in your seat, no ”just about dumped it” scenarios, just simple, fun fishing in a very stable boat. What could be cooler than that?

With the fore/aft balance point of the boat set right between the two drive trunks, there is but a very minimal change to boat pitch when you change the direction you face.

The Nagare 17 is further designed to accept an insulated and watertight tank between the two aka tubes where they run through the aft deck. You can use this for all kinds of stuff like: your catch, fresh bait storage, cold beverages if you catch and release… whatever suits your needs. There is plenty of room between the two drive trunks for a pretty good sized tackle box and lots of room up forward of the trunks for any of that “other stuff” that fishermen seem to sneak aboard their boats.

Nagare 17 aft low obl w

A moveable electronics unit can be fastened at the forward end of the cockpit, or unhooked and moved around aft if you’d rather have it facing that way.

Maybe you want to cast lures or flies instead of troll. The boat is so stable with the two, wide set amas, that you can stand up and cast all day without ever feeling like you are getting the least bit tippy. All in all, the Nagare 17 is quite a boat for fishing, as well as just plain fun, recreational pursuits.

The Nagare sisters represent a unique design family for human powered vessels. They are quick, stable and with their unique styling, represent a distinct departure from the looks of traditional boats one typically sees on any given shore or launch ramp. Both boats are designed to be built in marine ply Stitch and Glue methods for the hull sections, with cedar stripped decks to take advantage of the really beautiful, smooth curves capable from that style of building. You can paint the lower sections of the hull and leave the cedar decks natural with a deep varnished finshed, for a real knock-out boat that will really gather a crowd.If you really want to have a plywood deck build instead of the cedar strip build, write and twist my arm gently. I can design that change for those who really like to build that way

Plans are not yet complete, so if you would like to build one of these two boats, please send me an email and I’ll put your name on the mailing list for information, or watch the plans section of Duckworks for the notice.

CHRIS OSTLIND
LUNADA DESIGN
CHRIS@WEDGESAIL.COM