Using three 8x1 1/2in screws, affix the seat supports to the underside of the seat. If using a countersink, make sure this is done before screwing on the supports

To get the Ironbridge's 'egg' shape, cut the edges of the seat and seat supports as shown in the diagram below (the side of the seat with the cutout edges will be at the rear of the coracle)

Using a tape measure, find the center point of the seat. Mark this, and a point 9in (approx 23cm) either side of the centre point along the centre line of the seat (if using a larger 48" wide seat, the distance should be increased to 10in - approx 25cm). Drill pilot holes at these points, then affix the seat posts to the underside of the seat using one 8x2 1/2in screw per post (these are the black dots in the above diagram). If using a countersink, make sure this is done prior to screwing on the seat posts