I notice that all this information is about building the frame of the coracle out of thin strips of wood. I much prefer building it out of willow withies.
You just stick them into the ground in an oval, and then weave a basket with them. You bend them over to make the bowl. Then you lever your basket out of the ground, tidy up the rim, and stretch calico tightly over it, and stitch it in place.
Then you tar the calico, and put in your seat/fish stall.
Couple of days work. Great fun.