Swamp Thing looks fairly sleek in some ways, but has low freeboard and holds only one person.  We wanted to be able to go rowing together, but we also wanted to be able to pick the boats up and put them in the back of a small truck.  That meant we each needed our own boat.  And she didn't want a copy of Swamp Thing.

So I started building models with stiff paper and scotch tape.  I'd start by drawing a 4 x 8 inch rectangle (a.k.a. a 1/12 scale sheet of plywood), cutting parts out, and taping them together into small skiffs.  I'd show them to her and she'd tell me what changes to make.  Eventually we got to the design she was willing to build.

So we both started building, and with mine done I'm pleased enough with it to show it off.  Hers isn't done yet, but hopefully next summer we can go rowing together.

The Ensign's Gig, my version of our joint designed skiff, is made from two sheets of plywood.  The sides are 1/4" and the bottom 3/8".  If I were doing it again, I'd probably go for 1/4" on the bottom too to lighten her up a bit.   I used ACX, but it was unusually good quality. 

The name is one I've been meaning to use since I was an Ensign, ten years ago.  Navy types will get the joke and I once saw someone nearly fall of the dock laughing.  Civilians mostly don't get it.  Due to it's size, Katey is thinking of calling hers "Carl Vinson".

Cut diagram for side/stern pieces.

I cut the plywood as shown.  If you think about this a minute, you'll realize that the drawing doesn't make allowances for the saw kerf.  I cut the transom a little short and used the framing, the stern rub rail, and some thickened resin to make up the difference.

transom diagram

I framed the transom with 1 x 2 to provide a nailing surface and then beveled the edges to what I thought would be adequate for the sides to join evenly once everything went together.  I didn't allow enough and again had to fill with thickened resin, but these are the angles I measured once the boat was finished.  The plywood goes on the outside.

mid-ship frame diagram

I built a frame to form the boat around.  The side pieces end up being longer than necessary and get trimmed later in the building process.  I drew this out on a big piece of cardboard first to get the angles right, then cut the plywood knees and used them to align the side angles.  I probably lost some accuracy but it still worked fine. 

Both the transom frame and mid-ship frame were put together with bronze ring nails and adhesive out of a caulk tube.  Which adhesive one would use depends on budget, projected use of the boat, and how long one wants it to last.

Finally I ripped a bevel on the sides of a piece of 2 x 4.

stem cut angle diagram

I could have done this thinner and had a sharper stem, but I put an outer oak stem on later and it's sharp enough to cut the water but blunt enough to take running into things gracefully.  Regardless, the exact width is unimportant.

I assembled the whole thing by gluing and nailing the sides to the transom, then to the mid-ship frame, and then using a spanish windlass to bring the bow together and gluing and nailing to the stem, which was left oversize on the bottom until after the glue dried.  The mid-ship frame is installed 36" from the transom along the rail, 32" from the transom along the chine.

I had also notched the corners of the mid-ship frame to accept chine logs, which went in next.  Much of the wood used was thin strips of clear grain hardwood from a local cabinet shop waste pile.  The chine logs were something fairly soft for easy nailing and 1" x 1/2".  I didn't steam anything.  The strips had to be thin enough to bend easily and have good enough grain to put up with this treatment.

If someone wanted to build one of these more easily they could put the chine logs on the outside.  I think it might have slightly more drag that way and wouldn't look as good, but it would be easier to build.  There's another consideration too: After I put the bottom on I rounded the corners and taped them with 4" fiberglass tape.  That would be harder to do with an exterior chine log.   Another option would be to do the bottom stitch and glue style and eliminate the chine logs altogether.

Before the bottom went on the sides had to be beveled to a straight line.  Putting a straight edge athwart ships, the chines and sides were adjusted with a block plane and belt sander so the bottom would meet the chines flush, rather than just at the outer corner.  I trimmed the bottom of the stem to match at this point too.

The bottom went on by flopping the sheet of plywood over the boat as it rested upside down, tracing the outline onto that sheet, and then cutting it out oversized.

Assuming the wood all bends at the same rate, the boat should be symmetrical.  A builder could measure from bow to the stern corners to make sure before securing the bottom. 

Again I used glue and nails.  I started at the transom and worked forward.  I used a lot of nails for this on the transom, since pushing down the area at the bow levers up the stern.  I also had to concentrate on sending the nails in parallel to the side rather than perpendicular to the bottom.  When I failed to do this, the nails poked out of the side of the thin chine log inside the boat.   Once the glue dried I cut off the excess plywood and sanded over the edge to about a 1" radius.

Next I installed the quarter knees and breast hook.  These are the most tricky parts, since they have multiple angles, none of which are square.   I used a piece of oak plank from a pallet I found for stock, measured the angles, cut them slightly wrong, and then adjusted them with the belt sander.  Once they fit I adjusted them here and there to make them more comfortable to grab and fair into the corners.  Another way might have been to attach the inwales and gunwales, sand them down to a flat plane, and screw the breast hook and quarter knees down to them flat.

With those pieces on I attached the inwales and gunwales.  This was done in one maneuver using 3/8" x 1" oak strips (more cabinet shop scrap) for both.  I carefully cut the inwale to fit, and let the gunwale run a little long.   I applied glue, clamped everything in place, and drilled a pilot hole for each bronze ring-shank nail before nailing it through gunwale, plywood side, and inwale, using a small sledge hammer to back up the blows as I nailed.  I put a nail about every 4".  The advantage to this method was again that no steaming was needed.   The disadvantage was that it left the plywood edge exposed.

As I said above, the outer stem was cut to match the angle of the bow and attached, then the seams were reinforced with 4" fiberglass tape.  The whole outside of the hull was coated with resin, and then given three coats of oil based paint over a coat of primer.  I keep meaning to paint on a fake shear strake but haven't gotten to it yet.  The rails I left bright with four coats of spar varnish.   So far the plywood is darkening only slightly.  If I had a boat house or stored it covered there would be less of a problem.

I had some crazy notion of sailing so I installed a keel, a mast step and partners, and a rudder.  I didn't want to mess around with a dagger board, so I put on a long keel made from a cedar 5/4 x 6.  On the bottom of the keel I put an oak wear strip so that I could drag her over beaches and rocks.  The picture at the top of this article shows launching day, with the boat resting on its keel, and its bottom well off the cobble beach.  There are also rub strips on each side so that on a flat surface, the boat rests with no plywood on the ground.  The keel stiffens the bottom quite a bit too.

mast step

gig on blocks with sail rigged

The sail is a sprit rig made from closet pole stock spars and a white poly-tarp sail, sewn to give it some shape forward, and permanently mounted to the mast.   That makes it simple, but there's no way to lower sail underway.  The only way to reef is to remove the sprit pole and let the top flop down.

As it turned out the rudder I made (see it leaning against the building, above right) was undersized and the sail perhaps too big.  In a light wind it's okay, but strong winds make it hard to handle and there's no getting up in the bow underway for someone my size to take down the sail or make any sprit pole tension adjustments.  I tried a bigger rudder, but I think that the long keel and the uncertain center of lateral resistance with a large sailor moving around in a small boat make it unlikely that this boat will ever handle well under sail.  The mast step is all the way forward too, with the sail running nearly the full length of the boat.  When reaching, the sail torques the boat around and no amount of rudder can stop it.

Solutions to sailing problems might include rigging a jib of some sort off the opposite side when reaching or running to balance the torque, mounting a smaller sail amidships to reduce the torque, and using a dagger keel.

On the other hand, she rows great.  I can maintain 2 1/2 m.p.h. for several hours.  So far my armpits have chafed before my muscles have tired.  To row I sit on a padded removable box, just forward of the frame.  I use 6' 6" oars with leathered looms and turks-head buttons in standard open top oar locks set two feet forward from the transom and screwed directly into the rails without any further reinforcement.  

Katey and I once both got (carefully) into her (that's about 450 pounds) and in calm water with one astern and one forward she still had plenty of freeboard.  What's more, with the weight spread out some she was much more stable.  I imagine this would make a fine small tender.  Of course when I'm out solo I have to be careful leaning over the rail, because no matter how well the design works, the stability of a small light boat has it's limits.

One alteration I'm considering is cutting the keel down to about 3" amidships and even less forward.  Aft I'd run it out parallel to the waterline. It would still stiffen the bottom nicely and provide good tracking, but it would make it easier to launch from a shallowly sloped beach, make it slightly lighter to carry, and reduce a small amount of drag.

For a builder with limited budget and space and no boat trailer, a two sheet skiff like The Ensign's Gig is a great boat.  With the same or slightly better speed than Swamp Thing, better looks, better stability, and a shorter length that makes it easier to carry in my truck, The Ensign's Gig has completely replaced Swamp Thing.   I'm giving Swamp Thing to a young neighbor who's about 1/3 my weight.