Starting to mark off the second layer of marine plywood after trimming the first layer's edge level with the cabin sides and hatchway

Dry fitting the second layer over the first layer and marking the beam positions on the cabin sides before transferring them to the second layer of plywood 

The second layer is laid over the first only after the first layer as been trimmed with a router and then planed at the correct angle to the cabin sides 

The first two sections of plywood being clamped down into position so that the marks for the position of the beams can be transferred to the top layer of plywood so that the screw holes can be drilled through the plywood before fixing the plywood down on the first layer with epoxy glue.