The stern transom is made up of three layers of 6 ply, but each layer extends over a different area.

The outer layer is complete. The middle layer is T-shaped - the top of the 'T' doubles the thickness of the exposed section of the transom above the seat, while the lower section of the 'T' provides the core of the outboard motor reinforcement. The inner layer is just the central strip forming the outboard motor pad.

If you don't want to use an outboard motor, you can reduce the width of the middle and inner layers to 50 either side of the centreline - do not eliminate either of these payers, as they are needed to screw the rudder fittings into.

If you are not too concerned about weight, or will mostly use the scow with an outboard, you might like to make the transom a bit stronger. If so, you could make it from just two layers of 9 ply, using just the outer and middle layer parts of the drawing (but make the 'middle' layer one piece, not split into two).

All three layers are assembled by aligning the top edges of the parts and the centreline. 'Glue' the parts with an epoxy/microfibres mix and pin together while the 'glue' sets.

Add the three-piece seat bearer as shown. This is in three pieces as the central section goes on top of the inner layer of ply, while the other two go on top of the middle layer.

NOTE - Each ply layer is deeper and wider than the one before, as the boat gets wider and deeper as one moves forwards. Don't bother chamfering the edges of the assembled transom - the 'glue' used when assembling the hull will fill in these steps. The seat bearers are shown with a taper (ie, the front edge is wider than the back edge that is fixed to the transom) - this may not be really necessary, but it looks good!