Barton skiff...
15ft 4in, by 4ft 8in, by 650lbs displacement  outboard skiff
This boat has been designed by an amateur with no qualifications in boat design or boatbuilding and should be regarded as experimental. The designer accepts no liability for any loss or accident that may result from following these instructions or their attendant plans or from any loss or accident that may follow from using this boat.
Design points
This little outboard skiff is designed to get a lot out of a small motor; it's not meant to plane but to be semi-planing – so should allow a knot or two more than its length would allow were it a pure displacement boat. It should be not be used with an outboard much above 5hp, and in fact the well aft will not accommodate outboard engines much bigger than this, and is not intended for rough water. It's not a dory and not a vee bottom, so please don't treat it as if it were! In any case, far too many accidents take place because outboards of the wrong size have been used, and far too many of these are fatal. 
Construction points
The Barton skiff is intended to be built using the stitch and glue method, but with cleats supporting the decks and seats, with a 'box girder' along the central line of the boat that is intended to ensure the bottom of the boat takes up the correct profile.
The panels needed to cover the 'girder' between the seats have not been included on the ply panels; these can easily be made up without drawings and I would recommend that they be made removable so that the area beneath can be cleared and cleaned out from time to time. 
The areas underneath should drain conveniently through holes marked on the ply panels, and all other enclosed areas should have at least two drain plugs, or better a drain plug and a rotating opening, both for storing gear and equipment that needs to be kept dry and to ensure a good flow of air when the boat is not in use. That means they must be removed to allow the air to circulate!
As always, it's best to build a model first. When marking out, if you find an odd dimension, don't cut anything – ask me first, as there's always a risk that there will be an error here and there.
I don't to create a parts schedule at the present time, as I don't think it would be particularly helpful because everyone seems to use very different quantities of everything, perhaps especially epoxy. 
Readers may with to read my book Ultrasimple Boatbuilding published by International Marine and available from high street and online bookstores.

Before going any further, it's important to check the size of the plywood available to you, as it comes in different sizes in different countries around the world. A sheet of ply in the UK and the USA is likely to be 4ft (1220mm) wide, and 8ft (2440mm) or a little more in length, and this is the size these plans are made for. However, in the rest of the world including Australia, New Zealand and continental Europe ply sizes can vary considerably.
I'd like also to emphasise the importance of model-making. I'd ask you to please make a model first as it will show how the boat will look but perhaps more importantly how each component part goes together and contributes it's pennyworth towards creating a usable boat with a rigid structure. 
The system of coordinates I use to define the shapes of the panels on the 4 by 8ft plywood panels is the aspect of the plans most likely to cause concern in the minds of boatbuilders. This is because the approach seems unfamiliar, but in fact the technique is straightforward – and is the same as the one most of us used to draw graphs when we were at school - though I'd argue that building a boat is a darn sight more fun than maths lessons. 
Each pair of coordinates describes a particular point on a plywood sheet. The first number (the X-coordinate) in each pair of coordinates is a measurement along the bottom of the sheet, while the second in the pair (the Y coordinate) is a measurement up from the bottom - that is along a line that is a right angle (or 90 degrees) from our point along the bottom.
Before plotting each of these coordinates one by one, I find it best to square off the material into twelve-inch squares, as it's so much easier to plot from your squaring off than it is to mark out each measurement from the panel edge, but also because it helps to show whether you material is really 8ft long. 
Ply is frequently a little longer than it's supposed to be, and if you don't remove the extra before starting to build the boat, you could be in trouble, with some components longer than others. 
For squaring off ply, I often like to use a drywall square, but a tape measure and the side and edge of another sheet of plywood will do the job perfectly well, if slightly less conveniently.
Once the lines have been drawn, you need to draw your cutting lines. I do this by first finding a flexible batten to help re-create create the curves, and I've found that perhaps the best thing to use is an 8ft plastic moulding of the kind one can buy in any do-it-yourself story.
To make the curves, drive small nails into the material at each of the plotted points, lay the batten along the nails, using weights to hold it up to the nails. When the batten is in place and reasonably secure, draw along the length of the cutting line using a soft carpenter's pencil. After a few hours of plotting and drawing, you should be able to see that the lines on your ply correspond to those on my plans.
I'd like to offer a final word of warning on marking out. There are a lot of coordinates to plot here, and that means there are a lot of opportunities to make mistakes, both for the builder and for the designer. If when you have plotted the points and drawn the lines there are any that don't look right, check them, and check them again. Remember the old carpenter's advice that one should measure two or three times before cutting once. If after all this checking you're in doubt and feel I may have made an error please contact me at gmatkin@clara.net - I don't want you to risk wasting material unnecessarily because of a mistake I have made.

The next job is to cut the material out, and to build the boat using the stitch and glue boatbuilding method, otherwise known as tack and tape construction. 
Anyone who has used this method before will see immediately how it will work with this design, but if any of you reading this haven't worked this way before I won't explain it here but I would recommend reading it up at almost any epoxy supplier's website. One example is the UK Epoxy website: http://www.epoxy-resins.co.uk/.  
I'd make only four general construction points.
First, these drawings have been created with the intention that the fore and aft sections of the bottom and sides should be joined by epoxy tape on either side of the join, rather than using butt blocks or a scarf. I often prefer this method for several reasons: it's easy and unlike using butt blocks, I don't afterwards have to cut the thickness of the butt block from any frames they happen to coincide with. If you do build this boat using butt blocks, you'll no doubt have to cut some material from the central frames to make up.
Second, I have drawn a plywood solid timber reinforcement for the bows of this lightweight boat. This may need to be trimmed a little so that the components can be stitched together  snugly. I would then reinforce the inside of the bows on each side with several thick layers of epoxy and tape. 
On the outside I'd suggest applying two single layers of wide tape so that each lap over the sharp edge of the bows and each other, and finally I'd apply another length of tape along the centre line, covering the lapped area you just created. 
Third, once the sides are bent around the frames, you'll find that the sides become slightly curved where they meet the frames, and that there will be a small gap between the frame and the side-plank. That's only to be expected from the geometry of the side planks. All you have to do is to make sure this gap gets well filled with epoxy and covered over with tape in the usual way. The joint will be as strong or stronger than a similar joint with no small gap.
Fourth, it's clearly impossible to make stitch and glue fillets inside a closed box. Instead, the seats must be supported by cleats – pieces of wood of say 1 by 1in running across the frames from one side of the boat to the other. Standard epoxy fillets should be used where the seats meet the sides of the hull.  
There are a several special construction features of this boat that require a little explanation.
Gunwales I'm very much in favour of gapped inwales - they make a boat very rigid, and they look good. For this boat I'd make them from 2in wide material by doubled ½ in material, with 1in blocks. You'll find that the frames I've drawn will leave a hard corner that you will want to round off. If you go for the gapped inwales, you'll need to work out your gaps so that they coincide with the ply frames. However, for many people they're no doubt a complication too far and heavier gunwales will be preferable. If you go for the heavy gunwale option, I'd suggest laminating two lengths of 1 by 2in material to make a gunwale that's close to two inches wide, with the outer layer made from some kind of suitable hardwood.

Doubled outboard frame stern This has to be strong and I'd prefer to double this part of the boat, particularly if there is any chance that it might be used with even a small outboard.
If you do have any questions, please contact me at gmatkin@clara.net.