Two Humpbacks belly up off Cape Cod. Both were doing the flipper slaps, though one had obvious scrapes on the flipper. It wasn't till reviewing the photos later that evening that I saw the water dripping off the injured flipper was tinged red with blood. Taken with a Nikon D800E and Nikon 80-200mm F2.8 zoom. Exposure was 1/1000 at F4.5 at 100mm.