I know this reply isn’t much help! My eldest son, now living overseas, would swim out off the beach with his wet suit on and come back within a few minutes with a huge crayfish. He seemed to be able to catch one from from just about anywhere. When we camped at Goose Bay, near Kaikoura, some of the campers would drop a cray pot or two over night. Sometimes they would be successful other times not. I have also been out on crayfishing boats when they have been lifting their pots. Many pots would come up with nothing in them; while one or two pots would catch quite a few!