It has been mentioned that there existed structures where several boats cooperated in different ways. These are the net-groups. By a net-group (amigumi) I will mean a group of at least two crews that cooperate by operating nets jointly. The equipment can either be owned individually or jointly by the fishermen themselves, or by a capitalist who does not take part in the fishing operations. It will be obvious that this definition of net-groups covers a wide range of different organization forms. I will therefore begin this chapter with a description of the more important net-groups found in Shingū today and in the past.