Place the seat on the work surface, seat posts facing up. Using a couple nails, affix a pair of laths to the side of the seat, at the front half (the front is the side without the taper cut out of the seat). They should align with the top of the seat and the seat's centre line. Bend the laths together around the front of the seat to the other side. The measurement from the front centre edge of the seat to the gunwale at the front of the boat should be around 26in (65cm).
When you have the curve right, use a clamp to temporary affix the front gunwale to the other side of the seat. Go round the gunwale, nailing (or stapling) through with 25mm nails from the outside of the boat, clenching them over on the inside of the gunwale. When at the other side of the boat, trim the excess laths at the seat's centre line and using a couple of nails, affix the gunwale to the seat. Repeat this process for the rear gunwale. The measurement should again be taken from the front centre edge of the seat
