After this Jesus revealed himself again to the disciples by the Sea of Tiberias, and he revealed himself in this way. Simon Peter, Thomas (called the Twin), Nathanael of Cana in Galilee, the sons of Zebedee, and two others of his disciples were together. Simon Peter said to them, “I am going fishing.” They said to him, “We will go with you.” They went out and got into the boat, but that night they caught nothing.
Just as day was breaking, Jesus stood on the shore; yet the disciples did not know that it was Jesus. Jesus said to them, “Children, do you have any fish?” They answered him, “No.” He said to them, “Cast the net on the right side of the boat, and you will find some.” So they cast it, and now they were not able to haul it in, because of the quantity of fish. That disciple whom Jesus loved therefore said to Peter, “It is the Lord!” When Simon Peter heard that it was the Lord, he put on his outer garment, for he was stripped for work, and threw himself into the sea. The other disciples came in the boat, dragging the net full of fish, for they were not far from the land, but about a hundred yards off. John 21
They are coming to grips with the resurrection, but they still have not learned the profound truth that apart from Christ they can do nothing (15:5), and so that night they caught nothing (cf. Lk. 5:5).
The Gospel according to John (The Pillar New Testament Commentary (PNTC)) . Eerdmans Publishing Co – A. Kindle Edition.