Blackwater 16

Thin Water Tunnel Hull design

Black Water bow low w

Recently, I put up an informative article on two, economy Jonboats; Swamper and Swamp King: http://lunadadesign.net/swamper-and-swamp-king/ Those boats were drawn to address a very simple and practical approach to a thin water, all-purpose utility skiff and there has been a very nice response from readers seeking plans.

Taking the Jonboat concept further, I got an email from a boating enthusiast asking if I had ever designed a tunnel hull boat along the lines of the Swamper. He indicated that he had seen a boat something like that which had been designed for very thin water work. The boat in question was a full 20’ in length and he felt that the size would be just too much for one guy to either pole around or man- handle in any kind of windy situation. So, he was asking if I had one like that about 16’ long.

It turned out that I did not, but weirdly enough, I had been tossing an idea around very much like his request for some time. He was kind enough to direct me to the www.bateau.com website where I could take a look at the fine design work of Jacques Mertens and his XF20. http://bateau.com/proddetail.php?prod=XF20#.VdpaH_lViko

To be completely candid, I felt that the XF20 was quite a nice boat in every respect except that I had a customer who was asking about one for his needs, which needed to be 4 feet shorter. I had already designed a full-tilt, 18’ vee hulled flats machine for fast runs across open, choppy bays and thin water poling sessions called The Flatsmonster.

 

Flatsmaster18 Aft Obl w

So, I took many of the ideas I had in the Flatsmonster design and the Swamper series and combined them with the really nice elements of the XF20 to create the Blackwater 16.
Because of this choice of bottom shapes, this boat will be a lot more fun if you try to take it across a choppy body of water at speed. The forward vee shape of the hull will allow for faster speeds in open water as it will help to cut through the waves rather than bounce over them. As a swamper’s poling machine, it will excel in the narrow backwaters and thin mangrove estuaries where some really prize fish hang out, well out of reach of conventional fishing boats.

 

This is a pocket tunnel hulled boat with a wide stance that can support two fishermen and all their gear in very, very thin water. The hull has defined, 8 degree vee sections up front to help break some of the light chop one might find on backwater sessions in the late afternoon. The run aft from amidships is very nearly flat to allow the boat to plane easily with a very small outboard.

Black Water bow obl above w

If you want to take this boat into the Bayou and hunt for a pig, you’ll find that the hull can carry a very sizeable load with ease. I can really see this design as perfect for a duck hunter. Just rig a short mast in the center of the hull and hang a camo net over the gunnels and you have room to spare underneath for your cooler, your gun selection and the battery powered TV with earphones.

I’m not going to go into the technical description of the pocket tunnel, as there is a wonderful paragraph on the functional aspects on the Bateau site. Needless to say, the tunnel allows the engine to be raised up higher than normal giving additional clearance in the water for the prop to run in shallow water.

Black Water below w

This means you can go further into the creeks in your boat while using the engine. That translates to being able to stay out longer and come home later because of the additional speed over a poled boat in really shallow water. I figure nearly four additional inches of water depth before you’ll have to shut it down and paddle compared to a conventional Jonboat.

I suggest that you don’t exceed 30 hp for an outboard on this boat so that you can maximize the potential of the thin water capability. It’ll run surprisingly good with a 10-20-hp engine and in thin water and tight quarters, a lot of power would just go to waste, anyway. There’s a tendency to install too big an outboard on most recreational boats. I’m hoping that most folks recognize that a lighter, more efficient engine is actually better all around for 90% of all the boating work you will need to do.

Black Water structure w

Construction of the boat is in stitch and glue style with 3/8” hull bottom panels, deck, seat and fishing surfaces and ¼” plywood everywhere else save the transom. There is a lightweight framework truss in the hull beneath the deck to give the boat longitudinal strength. The suggested bench seats and forward fishing platform also serve as flotation chambers to keep the boat afloat in case it is swamped. The builders of this boat have the potential to build the interior out anyway they would like beyond the supplied bench seat design, but the more they add, the heavier the boat gets and that starts to take away the thin water capability of the design.

As shown in the illustrations, there is a midships frame and a continuous surface deck. Under the deck are two, full length stringers. These additions provide for a near bullet-proof hull with an added benefit. If the hull skin were to be holed from an unseen underwater obstacle, the flooding would be confined to the area of the damage as the compartments under the deck are sealed from one another to provide flotation integrity. Yes, the boat is a little heavier, but the payoff is in the enhanced safety, and hull rigidity if you decide to take it up to faster planing speeds.

Black Water aft obl wThis is an easy boat to build and it will provide hundreds of hours of enjoyment for the owner, especially after he customizes the interior to suit his favorite applications and fits-out the boat with all the trick goodies for his recreational passion.I suggest that the boat be built with epoxy taped seams inside at all joints with a full layer of epoxy glass on the outside of the hull. Prudent builders will add a layer (or two) of extra glass at all the sharper, hard corners to protect them from the inevitable banging a boat of this type will receive during use.

Plans will be available in the next month from Duckworks and will run USD$75. They include full-sized paper templates and detailed instructions regarding any of the stuff that is not straight forward, simple. There is also a suggested layout map for nesting the panels efficiently. The templates allow you to simply scarf together the ends of the full sheets of plywood, layout the templates, trace a line around the edges and start cutting the hull panels. No lofting required and quite a bit of time saved plotting points and bending sticks.

Chris Ostlind
Lunada Design
Chris@Wedgesail.com

Swamper and Swamp King

A Superior Weapon for the Outdoorsman


Swamper King & Swamper

One day I was driving around the industrial area near my boat shop and happened to pass the local power boat center. Sitting out front of the store were two, rather homely looking aluminum skiffs that are typically used around Utah to hunt ducks and geese and perform general boating duties for outdoorsmen.

I had never really taken a good look at the type before as I had more pressing matters in front of me trying to finish the build on a sailboat. For some reason, I pulled over to just get an idea as to how these metal boats went together and to understand the shapes that went into the hull. Most folks refer to the form as a Jonboat, although I’ve also seen it as Johnsboat and Flat-Bottomed Skiff, by various other sources.

Jim Michalak’s version of this simple skiff has been a real hit with homebuilders and there’s a bunch of good reasons why that’s so. They’re easy to build, provide hours of trouble free operation with the simplest of outboards and can do just about anything you could ask for a utility boat.

I went home that night and dialed-up the design software and started fooling around with a few ideas as to how I would design one of these boats for my portfolio. The result is that I came up with two versions that are very much alike except that one is a bit longer than the other for added carrying capacity is.

Swamper

Swamper 15 bow obl wThis boat is designed to take advantage of the physical properties of the standard, 4×8’ sheet of plywood and make the most of the sheet goods while still imparting a bit of style and form enhancement to the hull shape.

Rather than design a straight, flat-bottomed hull, I chose to give the Swamper a very slight Vee shape for the underwater parts. This gives a somewhat better ride through choppy conditions such as those you would find on any small lake when the wind comes up. If you’ve ever ridden in a flat bottom hull while pushing through small waves and experienced the slamming effect that comes with a flat surface as it hits the oncoming wave, you already know what I mean by this.

The overall length of the boat is 15’5” and the overall beam is just a shade over 55”. The height is 22” along the sides with the gunnel rising from that height in a soft curve, yielding a bow that is only 28.5” above the floor of the boat.

The main components come out of seven total sheets of plywood. The two bottom panels are from 3/8” material and the rest of the boat is from ¼” stock with the exception of the transom which is built from two layers of 3/8” ply. The boat is epoxy filleted and taped on the inside and completely covered in epoxy glass on the outside surfaces. The build style is simple, stitch and glue with one butt joint connection to be made to get the full-length hull panels.

There is a full-length stringer at gunnel level and it is covered with a four-inch wide cap rail completely around the boat with the exception of the transom mounting location for the engine.

Swamper 15 aft obl wBuilt-in flotation chambers are installed throughout the hull, starting with a big standing platform in the bow that is suitable for fishing. The forward seat can be enclosed with watertight bulkheads as is the far aft seat platform. Two enclosed flotation boxes sit on either side of the engine splashwell. You can swamp this boat and it will not sink.

The flotation chambers can be easily adapted to provide on-board storage if the builder installs watertight hatches or inspection ports.

I feel that the optimal, outboard engine size for this boat would be in the 15-20HP range. It will work just fine with a smaller engine, though, as the boat is quite light. I’m sure somebody will hang something bigger than this, but I’m not recommending it.

Swamper 15 above w

The Swamper is perfect for fishing; hunting work related tasks on the water and just plain old fooling around. It can go into some pretty thin water with its draft of just under 7” at 650 pounds of displacement and can easily be setup with oars and a removable center seat for human powered applications.

If you live out in the country and have a good relationship with the local Sheriff, the Swamper will fit snugly between the wheel wells of the standard American pickup. With the tailgate down, you’ll have five feet of boat hanging out, but it is doable. Again, I’m not recommending the practice; just letting you know it can be done… if you’re so inclined.

Normal transport would be with a lightweight trailer, which would allow you to keep the outboard on the boat for short distances. A 15 Hp outboard doesn’t weight too much, but I prefer to see them removed from the transom for transport over long distances.


Swamp KingSwamper-Swamp King Comparison w

This boat is very much like the Swamper with virtually the same lines. The biggest differences are the length at 18’, the ability of the boat to carry more weight and the addition of an extra, installed seat with its enclosed flotation volume. With an extra layer of ¼” plywood on the transom, this boat can easily handle a 30-40 HP motor.

The costs to build the Swamp King are slightly greater due to the added plywood for the increased length and some additional trim, structural material as well as extra epoxy and glass.

Swamper-Swamp King Comp Bow w

Even though these are simple boats, they are capable of providing years of wonderful service to the owner/builder with only very minor maintenance. If you have a teenage son or daughter who likes to enjoy outdoor activities with you, this boat would make for a terrific joint project over the winter. Either the Swamper or the Swamp King would make an excellent first boat to hand down when one of them gets old enough to have a boat of their own.