I was fishing along Scusset Beach, Cape Cod about sun down when I hooked a fish. It didn't put up much of a fight, so I figured that it was a tinker mackerel since I had been catching those on and off. Then it came jumping way up out of the water. It was about 16"-18" long and silvery looking, but no stripes. It put up a weak fight but broke me off (20# flouro) at my feet after zooming 'round and 'round me. What the heck was it??